135134domain: NAppears in sequencesa(n) = n!! - 1.at n=13A128882Number of partitions of 2n such that (sum of parts having multiplicity 1) = sum of all other parts.at n=36A240447G.f.: 1 + Sum_{n>=1} a(n)*x^n/(1 - x^n) = 1/(1 - x/(1 - 2*x/(1 - 3*x/(1 - 4*x/(1 - ...))))).at n=6A286310