272293domain: NAppears in sequencesG.f. satisfies A(x) = 1 + x*cycle_index(Alt(4), A(x)).at n=16A036717Number of partitions of 2n in which every part is <n+1; also, the number of partitions of 2 into rational numbers a/b such that 0<a<=b<=n and b divides n.at n=25A209816