G.f. = Phi^5*F, where Phi = g.f. for A028930, F = g.f. for A028959.

Terms

a(0) =1a(1) =2a(2) =10a(3) =30a(4) =72a(5) =180a(6) =394a(7) =760a(8) =1474a(9) =2552a(10) =4312a(11) =6764a(12) =10664a(13) =15290a(14) =22764a(15) =31252a(16) =44134a(17) =58360a(18) =80192a(19) =101988a(20) =135852a(21) =169552a(22) =218968a(23) =267170a(24) =340142a(25) =406342a(26) =507626a(27) =600242a(28) =735996a(29) =856054