Partial sums of A101351.

Terms

a(0) =0a(1) =2a(2) =6a(3) =15a(4) =33a(5) =69a(6) =140a(7) =280a(8) =556a(9) =1101a(10) =2179a(11) =4315a(12) =8554a(13) =16978a(14) =33738a(15) =67115a(16) =133637a(17) =266305a(18) =531032a(19) =1059500a(20) =2114840a(21) =4222937a(22) =8434951a(23) =16852215a(24) =33675798a(25) =67305254a(26) =134535510a(27) =268949655a(28) =537702921a(29) =1075088061