117012

Appears in sequences

• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..3*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ) where T(n,k) equals the coefficient of x^k in (1+x+x^2+x^3)^n.at n=20A248876
• Expansion of e.g.f. 2*exp(-x) / (3 - exp(2*x)).at n=7A368454
• Number of unordered pairs (p,q) of distinct partitions of n such that the set of parts in q is equal to the set of parts in p.at n=33A369697