Sequences
392,541 sequences
- Number of partitions of n into distinct squares.A033461
Number of partitions of n into distinct squares.
- Exponential (or "EXP") transform of squares A000290.A033462
Exponential (or "EXP") transform of squares A000290.
- EXPCONV of squares A000290 with themselves.A033463
EXPCONV of squares A000290 with themselves.
- Logarithmic (or "LOG") transform of squares A000290.A033464
Logarithmic (or "LOG") transform of squares A000290.
- Numerators of the first differences of 1/(n^2 + 1).A033465
Numerators of the first differences of 1/(n^2 + 1).
- Denominators of the first differences of 1/(n^2 + 1).A033466
Denominators of the first differences of 1/(n^2 + 1).
- Partial sums of sequence {1/(i^2+1): i=0..n} (numerators).A033467
Partial sums of sequence {1/(i^2+1): i=0..n} (numerators).
- Partial sums of sequence {1/(i^2+1): i=0..n} (denominators).A033468
Partial sums of sequence {1/(i^2+1): i=0..n} (denominators).
- Denominator of Bernoulli(2n,1/2).A033469
Denominator of Bernoulli(2n,1/2).
- Numerator of Bernoulli(2n,1/3).A033470
Numerator of Bernoulli(2n,1/3).
- Denominator of Bernoulli(2n,1/3).A033471
Denominator of Bernoulli(2n,1/3).
- Number of n-vertex labeled graphs that are gracefully labeled trees.A033472
Number of n-vertex labeled graphs that are gracefully labeled trees.
- Numerator of (2*n+1)!*8*Bernoulli(2*n,1/2).A033473
Numerator of (2*n+1)!*8*Bernoulli(2*n,1/2).
- Duplicate of A001896.A033474
Duplicate of A001896.
- Denominator of Bernoulli(2n,1/4).A033475
Denominator of Bernoulli(2n,1/4).
- Squares of primes or products of pairs of consecutive primes.A033476
Squares of primes or products of pairs of consecutive primes.
- Products p^3 or p^2*q, where {p,q} are consecutive primes.A033477
Products p^3 or p^2*q, where {p,q} are consecutive primes.
- 3x+1 sequence beginning at 3.A033478
3x+1 sequence beginning at 3.
- 3x+1 sequence beginning at 9.A033479
3x+1 sequence beginning at 9.
- 3x + 1 sequence beginning at 15.A033480
3x + 1 sequence beginning at 15.
- 3x+1 sequence beginning at 21.A033481
3x+1 sequence beginning at 21.
- Expansion of (1+2*x-3*x^2-4*x^3+x^4)/(1-8*x^2+11*x^4).A033482
Expansion of (1+2*x-3*x^2-4*x^3+x^4)/(1-8*x^2+11*x^4).
- Number of disconnected 4-valent (or quartic) graphs with n nodes.A033483
Number of disconnected 4-valent (or quartic) graphs with n nodes.
- a(n) = 3*2^n - 2.A033484
a(n) = 3*2^n - 2.
- a(n) = a(n-1) + a(floor(n/2)), a(1) = 1.A033485
a(n) = a(n-1) + a(floor(n/2)), a(1) = 1.
- a(n) = n*(n + 1)*(n + 2)*(n + 3)/2.A033486
a(n) = n*(n + 1)*(n + 2)*(n + 3)/2.
- a(n) = n*(n+1)*(n+2)*(n+3)/4.A033487
a(n) = n*(n+1)*(n+2)*(n+3)/4.
- a(n) = n*(n+1)*(n+2)*(n+3)/6.A033488
a(n) = n*(n+1)*(n+2)*(n+3)/6.
- a(1) = 1, a(n) = 2*a(n-1) + a([n/2]).A033489
a(1) = 1, a(n) = 2*a(n-1) + a([n/2]).
- a(n) = 2*a(n-1) + a(floor(n/2)), with a(1) = 1, a(2) = 2.A033490
a(n) = 2*a(n-1) + a(floor(n/2)), with a(1) = 1, a(2) = 2.
- a(n) is the smallest integer that takes n halving and tripling steps to reach 1 in the 3x+1 problem.A033491
a(n) is the smallest integer that takes n halving and tripling steps to reach 1 in the 3x+1 problem.
- Record number of steps to reach 1 in '3x+1' problem, corresponding to starting values in A006877 (same as A006878 except here we start counting at 1 instead of 0).A033492
Record number of steps to reach 1 in '3x+1' problem, corresponding to starting values in A006877 (same as A006878 except here we start counting at 1 instead of 0).
- Sum of the numbers in the trajectory of n for the 3x+1 problem.A033493
Sum of the numbers in the trajectory of n for the 3x+1 problem.
- Record sum of numbers in trajectory of 3x+1 problem.A033494
Record sum of numbers in trajectory of 3x+1 problem.
- Initial number for record sum of numbers in trajectory of 3x+1 problem.A033495
Initial number for record sum of numbers in trajectory of 3x+1 problem.
- Numbers m that are the largest number in their Collatz (3x+1) trajectory.A033496
Numbers m that are the largest number in their Collatz (3x+1) trajectory.
- a(n) = 2*a(n-1) + a(floor(n/2)), with a(1) = 1, a(2) = 2, a(3) = 4.A033497
a(n) = 2*a(n-1) + a(floor(n/2)), with a(1) = 1, a(2) = 2, a(3) = 4.
- a(n) = a(n-1)+ a(round(2*(n-1)/3)) +a(round((n-1)/3)) starting a(1)=1.A033498
a(n) = a(n-1)+ a(round(2*(n-1)/3)) +a(round((n-1)/3)) starting a(1)=1.
- a(n) = a(n-1) + a(round(2*(n-1)/3)) + a(round((n-1)/3)) with a(1)=a(2)=1.A033499
a(n) = a(n-1) + a(round(2*(n-1)/3)) + a(round((n-1)/3)) with a(1)=a(2)=1.
- a(n) = a(n-1) + a(round(2*(n-1)/3)) + a(round((n-1)/3)) with a(1)=1, a(2)=2.A033500
a(n) = a(n-1) + a(round(2*(n-1)/3)) + a(round((n-1)/3)) with a(1)=1, a(2)=2.
- Almost-squares: m such that m/p(m) >= k/p(k) for all k<m, where p(m) is the least perimeter of a rectangle with integer side lengths and area m.A033501
Almost-squares: m such that m/p(m) >= k/p(k) for all k<m, where p(m) is the least perimeter of a rectangle with integer side lengths and area m.
- Carmichael numbers of the form (6*k+1)*(12*k+1)*(18*k+1), where 6*k+1, 12*k+1 and 18*k+1 are all primes.A033502
Carmichael numbers of the form (6*k+1)*(12*k+1)*(18*k+1), where 6*k+1, 12*k+1 and 18*k+1 are all primes.
- First differences of A046025.A033503
First differences of A046025.
- a(n)/4^n is the expected number of tosses of a coin required to obtain n+1 heads or n+1 tails.A033504
a(n)/4^n is the expected number of tosses of a coin required to obtain n+1 heads or n+1 tails.
- Expansion of 1/(1 - 3*x - x^2 + x^3).A033505
Expansion of 1/(1 - 3*x - x^2 + x^3).
- Number of matchings in graph P_{3} X P_{n}.A033506
Number of matchings in graph P_{3} X P_{n}.
- Number of matchings in graph P_{4} X P_{n}.A033507
Number of matchings in graph P_{4} X P_{n}.
- Number of matchings in graph P_{5} X P_{n}.A033508
Number of matchings in graph P_{5} X P_{n}.
- Number of matchings in graph P_{6} X P_{n}.A033509
Number of matchings in graph P_{6} X P_{n}.
- Number of matchings in graph P_{7} X P_{n}.A033510
Number of matchings in graph P_{7} X P_{n}.