Partial sums of A051740.

Terms

a(0) =1a(1) =12a(2) =57a(3) =182a(4) =462a(5) =1008a(6) =1974a(7) =3564a(8) =6039a(9) =9724a(10) =15015a(11) =22386a(12) =32396a(13) =45696a(14) =63036a(15) =85272a(16) =113373a(17) =148428a(18) =191653a(19) =244398a(20) =308154a(21) =384560a(22) =475410a(23) =582660a(24) =708435a(25) =855036a(26) =1024947a(27) =1220842a(28) =1445592a(29) =1702272