Sequences

392,541 sequences

Largest metadrome (number with digits in strict ascending order) in base n.A023811
Largest metadrome (number with digits in strict ascending order) in base n.
Duplicate of A062813.A023812
Duplicate of A062813.
a(n) = n^(n*(n+1)/2).A023813
a(n) = n^(n*(n+1)/2).
Number of associative binary operations on an n-set; number of labeled semigroups.A023814
Number of associative binary operations on an n-set; number of labeled semigroups.
Number of binary operations on an n-set that are commutative and associative; labeled commutative semigroups.A023815
Number of binary operations on an n-set that are commutative and associative; labeled commutative semigroups.
Sum of exponents in prime-power factorization of C(2n,n).A023816
Sum of exponents in prime-power factorization of C(2n,n).
Sum of exponents in prime-power factorization of C(2n,n-1).A023817
Sum of exponents in prime-power factorization of C(2n,n-1).
Sum of exponents in prime-power factorization of C(2n,n-2).A023818
Sum of exponents in prime-power factorization of C(2n,n-2).
Sum of exponents in prime-power factorization of C(3n,n).A023819
Sum of exponents in prime-power factorization of C(3n,n).
Sum of exponents in prime-power factorization of C(3n,n-1).A023820
Sum of exponents in prime-power factorization of C(3n,n-1).
Sum of exponents in prime-power factorization of C(3n,n-2).A023821
Sum of exponents in prime-power factorization of C(3n,n-2).
Sum of exponents in prime-power factorization of C(3n,n-3).A023822
Sum of exponents in prime-power factorization of C(3n,n-3).
Sum of exponents in prime-power factorization of C(3n,n+1).A023823
Sum of exponents in prime-power factorization of C(3n,n+1).
Sum of exponents in prime-power factorization of C(3n,n+2).A023824
Sum of exponents in prime-power factorization of C(3n,n+2).
Sum of exponents in prime-power factorization of C(3n,n+3).A023825
Sum of exponents in prime-power factorization of C(3n,n+3).
Sum of exponents in prime-power factorization of C(4n,n).A023826
Sum of exponents in prime-power factorization of C(4n,n).
Sum of exponents in prime-power factorization of C(4n,n-1).A023827
Sum of exponents in prime-power factorization of C(4n,n-1).
Sum of exponents in prime-power factorization of C(4n,n-2).A023828
Sum of exponents in prime-power factorization of C(4n,n-2).
Sum of exponents in prime-power factorization of C(4n,n-3).A023829
Sum of exponents in prime-power factorization of C(4n,n-3).
Sum of exponents in prime-power factorization of C(4n,n-4).A023830
Sum of exponents in prime-power factorization of C(4n,n-4).
Sum of exponents in prime-power factorization of C(4n,n+1).A023831
Sum of exponents in prime-power factorization of C(4n,n+1).
Sum of exponents in prime-power factorization of C(4n,n+2).A023832
Sum of exponents in prime-power factorization of C(4n,n+2).
Sum of exponents in prime-power factorization of C(4n,n+3).A023833
Sum of exponents in prime-power factorization of C(4n,n+3).
Sum of exponents in prime-power factorization of C(4n,2n).A023834
Sum of exponents in prime-power factorization of C(4n,2n).
Sum of exponents in prime-power factorization of C(4n,2n-1).A023835
Sum of exponents in prime-power factorization of C(4n,2n-1).
Sum of exponents in prime-power factorization of C(4n,2n-2).A023836
Sum of exponents in prime-power factorization of C(4n,2n-2).
Sum of exponents in prime-power factorization of C(5n,n).A023837
Sum of exponents in prime-power factorization of C(5n,n).
Sum of exponents in prime-power factorization of C(5n,n-1).A023838
Sum of exponents in prime-power factorization of C(5n,n-1).
Sum of exponents in prime-power factorization of C(5n,n-2).A023839
Sum of exponents in prime-power factorization of C(5n,n-2).
Sum of exponents in prime-power factorization of C(5n,n-3).A023840
Sum of exponents in prime-power factorization of C(5n,n-3).
Sum of exponents in prime-power factorization of C(5n,n-4).A023841
Sum of exponents in prime-power factorization of C(5n,n-4).
Sum of exponents in prime-power factorization of C(5n,n-5).A023842
Sum of exponents in prime-power factorization of C(5n,n-5).
Sum of exponents in prime-power factorization of C(5n,n+1).A023843
Sum of exponents in prime-power factorization of C(5n,n+1).
Sum of exponents in prime-power factorization of C(5n,n+2).A023844
Sum of exponents in prime-power factorization of C(5n,n+2).
Sum of exponents in prime-power factorization of binomial(5n, n+3).A023845
Sum of exponents in prime-power factorization of binomial(5n, n+3).
Sum of exponents in prime-power factorization of binomial(5n, n+4).A023846
Sum of exponents in prime-power factorization of binomial(5n, n+4).
Sum of exponents in prime-power factorization of binomial(5n, 2n).A023847
Sum of exponents in prime-power factorization of binomial(5n, 2n).
Sum of exponents in prime-power factorization of binomial(5n, 2n-1).A023848
Sum of exponents in prime-power factorization of binomial(5n, 2n-1).
Sum of exponents in prime-power factorization of binomial(5n, 2n-2).A023849
Sum of exponents in prime-power factorization of binomial(5n, 2n-2).
Sum of exponents in prime-power factorization of binomial(5n, 2n+1).A023850
Sum of exponents in prime-power factorization of binomial(5n, 2n+1).
Sum of exponents in prime-power factorization of binomial(5n, 2n+2).A023851
Sum of exponents in prime-power factorization of binomial(5n, 2n+2).
Sum of exponents in prime-power factorization of binomial(6n, n).A023852
Sum of exponents in prime-power factorization of binomial(6n, n).
Sum of exponents in prime-power factorization of binomial(6n, 2n).A023853
Sum of exponents in prime-power factorization of binomial(6n, 2n).
Sum of exponents in prime-power factorization of binomial(6n, 3n).A023854
Sum of exponents in prime-power factorization of binomial(6n, 3n).
a(n) = 1*(n) + 2*(n-1) + 3*(n-2) + ... + (n+1-k)*k, where k = floor((n+1)/2).A023855
a(n) = 1*(n) + 2*(n-1) + 3*(n-2) + ... + (n+1-k)*k, where k = floor((n+1)/2).
a(n) = 1*(n+1-1) + 2*(n+1-2) + ... + k*(n+1-k), where k = floor((n+1)/2).A023856
a(n) = 1*(n+1-1) + 2*(n+1-2) + ... + k*(n+1-k), where k = floor((n+1)/2).
a(n) = 1*(n+3-1) + 2*(n+3-2) + .... + k*(n+3-k), where k=floor((n+1)/2).A023857
a(n) = 1*(n+3-1) + 2*(n+3-2) + .... + k*(n+3-k), where k=floor((n+1)/2).
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k = floor((n+1)/2), t = A023531.A023858
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k = floor((n+1)/2), t = A023531.
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2), and t = A023532.A023859
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2), and t = A023532.
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2), t = A000045 (Fibonacci numbers).A023860
a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2), t = A000045 (Fibonacci numbers).