Sequences
392,541 sequences
- Number of partitions of n into parts of 13 kinds.A023011
Number of partitions of n into parts of 13 kinds.
- Number of partitions of n into parts of 14 kinds.A023012
Number of partitions of n into parts of 14 kinds.
- Number of partitions of n into parts of 15 kinds.A023013
Number of partitions of n into parts of 15 kinds.
- Number of partitions of n into parts of 16 kinds.A023014
Number of partitions of n into parts of 16 kinds.
- Number of partitions of n into parts of 17 kinds.A023015
Number of partitions of n into parts of 17 kinds.
- Number of partitions of n into parts of 18 kinds.A023016
Number of partitions of n into parts of 18 kinds.
- Number of partitions of n into parts of 19 kinds.A023017
Number of partitions of n into parts of 19 kinds.
- Number of partitions of n into parts of 20 kinds.A023018
Number of partitions of n into parts of 20 kinds.
- Number of partitions of n into parts of 21 kinds.A023019
Number of partitions of n into parts of 21 kinds.
- Number of partitions of n into parts of 22 kinds.A023020
Number of partitions of n into parts of 22 kinds.
- Number of partitions of n into parts of 23 kinds.A023021
Number of partitions of n into parts of 23 kinds.
- Number of partitions of n into two relatively prime parts. After initial term, this is the "half-totient" function phi(n)/2 (A000010(n)/2).A023022
Number of partitions of n into two relatively prime parts. After initial term, this is the "half-totient" function phi(n)/2 (A000010(n)/2).
- Number of partitions of n into 3 unordered relatively prime parts.A023023
Number of partitions of n into 3 unordered relatively prime parts.
- Number of partitions of n into 4 unordered relatively prime parts.A023024
Number of partitions of n into 4 unordered relatively prime parts.
- Number of partitions of n into 5 unordered relatively prime parts.A023025
Number of partitions of n into 5 unordered relatively prime parts.
- Number of partitions of n into 6 unordered relatively prime parts.A023026
Number of partitions of n into 6 unordered relatively prime parts.
- Number of partitions of n into 7 unordered relatively prime parts.A023027
Number of partitions of n into 7 unordered relatively prime parts.
- Number of partitions of n into 8 unordered relatively prime parts.A023028
Number of partitions of n into 8 unordered relatively prime parts.
- Number of partitions of n into 9 unordered relatively prime parts.A023029
Number of partitions of n into 9 unordered relatively prime parts.
- Number of partitions of n into 10 unordered relatively prime parts.A023030
Number of partitions of n into 10 unordered relatively prime parts.
- Number of compositions of n into 6 ordered relatively prime parts.A023031
Number of compositions of n into 6 ordered relatively prime parts.
- Number of compositions of n into 7 ordered relatively prime parts.A023032
Number of compositions of n into 7 ordered relatively prime parts.
- Number of compositions of n into 8 ordered relatively prime parts.A023033
Number of compositions of n into 8 ordered relatively prime parts.
- Number of compositions of n into 9 ordered relatively prime parts.A023034
Number of compositions of n into 9 ordered relatively prime parts.
- Number of compositions of n into 10 ordered relatively prime parts.A023035
Number of compositions of n into 10 ordered relatively prime parts.
- Smallest positive even integer that is an unordered sum of two primes in exactly n ways.A023036
Smallest positive even integer that is an unordered sum of two primes in exactly n ways.
- a(n) = n^0 + n^1 + ... + n^(n-1), or a(n) = (n^n-1)/(n-1) with a(0)=0; a(1)=1.A023037
a(n) = n^0 + n^1 + ... + n^(n-1), or a(n) = (n^n-1)/(n-1) with a(0)=0; a(1)=1.
- a(n) = 12*a(n-1) - a(n-2).A023038
a(n) = 12*a(n-1) - a(n-2).
- a(n) = 18*a(n-1) - a(n-2).A023039
a(n) = 18*a(n-1) - a(n-2).
- w such that w^3+x^3+y^3+z^3=0, w>|x|>|y|>|z|, is soluble (all solutions).A023040
w such that w^3+x^3+y^3+z^3=0, w>|x|>|y|>|z|, is soluble (all solutions).
- w such that w^3 = x^3+y^3+z^3, x>y>z>=0, is soluble (primitive solutions).A023041
w such that w^3 = x^3+y^3+z^3, x>y>z>=0, is soluble (primitive solutions).
- Numbers whose cube is the sum of three distinct nonnegative cubes.A023042
Numbers whose cube is the sum of three distinct nonnegative cubes.
- 6th differences of factorial numbers.A023043
6th differences of factorial numbers.
- 7th differences of factorial numbers.A023044
7th differences of factorial numbers.
- 8th differences of factorial numbers.A023045
8th differences of factorial numbers.
- 9th differences of factorial numbers.A023046
9th differences of factorial numbers.
- 10th differences of factorial numbers.A023047
10th differences of factorial numbers.
- Smallest prime having least positive primitive root n, or 0 if no such prime exists.A023048
Smallest prime having least positive primitive root n, or 0 if no such prime exists.
- Smallest prime > n having primitive root n, or 0 if no such prime exists.A023049
Smallest prime > n having primitive root n, or 0 if no such prime exists.
- Sum of two coprime cubes in at least three ways.A023050
Sum of two coprime cubes in at least three ways.
- Numbers that are the sum of two positive cubes in at least four ways (all solutions).A023051
Numbers that are the sum of two positive cubes in at least four ways (all solutions).
- Perfect Digital Invariants: numbers that are the sum of some fixed power of their digits.A023052
Perfect Digital Invariants: numbers that are the sum of some fixed power of their digits.
- Number of noncrossing rooted trees with n nodes on a circle that do not have leaves at level 1.A023053
Number of noncrossing rooted trees with n nodes on a circle that do not have leaves at level 1.
- Simon Plouffe's conjectured extension of sequence A008368.A023054
Simon Plouffe's conjectured extension of sequence A008368.
- (Apparently) differences between adjacent perfect powers (integers of form a^b, a >= 1, b >= 2).A023055
(Apparently) differences between adjacent perfect powers (integers of form a^b, a >= 1, b >= 2).
- a(n) is least k such that k and k+n are adjacent nontrivial powers of positive integers, or 0 if no such k apparently exists.A023056
a(n) is least k such that k and k+n are adjacent nontrivial powers of positive integers, or 0 if no such k apparently exists.
- (Apparently) not the difference between adjacent perfect powers (A001597, integers of form a^b, a >= 1, b >= 2).A023057
(Apparently) not the difference between adjacent perfect powers (A001597, integers of form a^b, a >= 1, b >= 2).
- Positive numbers k such that k and 2*k are anagrams of each other in base 3 (k is written here in base 3).A023058
Positive numbers k such that k and 2*k are anagrams of each other in base 3 (k is written here in base 3).
- Positive numbers k such that k and 2*k are anagrams in base 4 (written in base 4).A023059
Positive numbers k such that k and 2*k are anagrams in base 4 (written in base 4).
- Positive numbers k such that k and 3*k are anagrams in base 4 (written in base 4).A023060
Positive numbers k such that k and 3*k are anagrams in base 4 (written in base 4).