125028domain: NAppears in sequencesNumber of proper T_1-hypergraphs with 3 labeled nodes and n hyperedges.at n=24A056078Values of m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,57.at n=28A065697Expansion of e.g.f. ( (1/x) * Series_Reversion( x*(1 + x*log(1-x))^3 ) )^(2/3).at n=6A376387