44826624

Appears in sequences

• a(n) = binomial(n,2) * 2^(n-1).at n=19A001815
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} A200536(n,2*n-k)^2 * x^k] / A(x)^n * x^n/n ), where A200536(n,2*n-k) is the coefficient of x^k in (2+3*x+x^2)^n.at n=35A251689
• a(n) is the number of subsets of {1,2,...,n} that contain exactly two odd numbers.at n=36A330592
• Number of runs of 1's of length <= 3 over all binary strings of length n.at n=23A386878