Partial sums of A152891.

Terms

a(0) =0a(1) =2a(2) =11a(3) =40a(4) =123a(5) =349a(6) =951a(7) =2539a(8) =6710a(9) =17645a(10) =46290a(11) =121302a(12) =317706a(13) =831920a(14) =2178173a(15) =5702734a(16) =14930181a(17) =39087979a(18) =102333945a(19) =267914065a(20) =701408480a(21) =1836311627a(22) =4807526676a(23) =12586268700a(24) =32951279748a(25) =86267570894a(26) =225851433311