Subsequence of A005428 with state = 1.

Terms

a(0) =1a(1) =4a(2) =6a(3) =9a(4) =31a(5) =70a(6) =105a(7) =355a(8) =799a(9) =1798a(10) =2697a(11) =9103a(12) =20482a(13) =30723a(14) =69127a(15) =155536a(16) =233304a(17) =349956a(18) =524934a(19) =787401a(20) =2657479a(21) =5979328a(22) =8968992a(23) =13453488a(24) =20180232a(25) =30270348a(26) =45405522a(27) =68108283a(28) =153243637a(29) =1745540806