269128937220
domain: N
Appears in sequences
- a(n) = binomial(2*n+1, n+1): number of ways to put n+1 indistinguishable balls into n+1 distinguishable boxes = number of (n+1)-st degree monomials in n+1 variables = number of monotone maps from 1..n+1 to 1..n+1.at n=20A001700
- a(n) = binomial(4*n+1, 2*n).at n=10A002458
- Binomial coefficient C(41,n).at n=20A010957
- Binomial coefficient C(41,n).at n=21A010957
- a(n) = binomial(n,20).at n=21A010973
- a(n) = binomial(n,21).at n=20A010974
- Number of reversible strings with n-1 black beads and n-1 white beads. String is not palindromic.at n=21A032095
- Number of 2n-bead black-white reversible strings with n black beads.at n=21A032123
- a(n) = 1/2*binomial(2*n,n) - (1+(-1)^n)/4*(binomial(n,floor(n/2)))^2.at n=21A058621
- Largest term in the prime(n)-th row of Pascal's triangle, prime(n) being the n-th prime.at n=12A075890
- Total number of leaves in all rooted ordered trees with n edges.at n=21A088218
- a(n) = Sum_{k=0..n} C(n,k)^2*mod(k,2).at n=21A110145
- Number of n-element subsets of [2n] having an even sum.at n=21A119358
- The number of Motzkin n-paths with exactly one flat step.at n=41A138364
- a(n) = Sum_{k=0..floor(n/2)} binomial(n, k)^2.at n=21A277247
- a(n) equals the coefficient of x^n in Sum_{m>=0} (x^m + 1/x^m)^m for n > 0.at n=40A304638
- a(n) equals the coefficient of x^(2*n-1) in Sum_{m>=0} (x^m + 1/x^m)^m for n >= 1.at n=20A316596
- Number of compositions of n into n nonnegative parts such that their xor-sum is not zero.at n=21A372871