40108032

Appears in sequences

• Theta series of D*_18 lattice.at n=17A022071
• a(n) = 2^n*binomial(n,2).at n=18A100381
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} A200536(n,k)^2 * x^k] / A(x)^n * x^n/n ), where A200536(n,k) is the coefficient of x^k in (1+3*x+2*x^2)^n.at n=36A200537
• 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=36A251689
• a(n) is the number of subsets of {1,2,...,n} that contain exactly two odd numbers.at n=35A330592