Partial sums of A027941(n-1) with a(-1) = 0.

Terms

a(0) =0a(1) =0a(2) =1a(3) =5a(4) =17a(5) =50a(6) =138a(7) =370a(8) =979a(9) =2575a(10) =6755a(11) =17700a(12) =46356a(13) =121380a(14) =317797a(15) =832025a(16) =2178293a(17) =5702870a(18) =14930334a(19) =39088150a(20) =102334135a(21) =267914275a(22) =701408711a(23) =1836311880a(24) =4807526952a(25) =12586269000a(26) =32951280073a(27) =86267571245a(28) =225851433689a(29) =591286729850