Convolution of A002024 with itself.

Terms

a(0) =1a(1) =4a(2) =8a(3) =14a(4) =22a(5) =30a(6) =41a(7) =54a(8) =67a(9) =82a(10) =99a(11) =118a(12) =138a(13) =160a(14) =182a(15) =206a(16) =234a(17) =262a(18) =292a(19) =322a(20) =353a(21) =388a(22) =425a(23) =462a(24) =501a(25) =542a(26) =583a(27) =626a(28) =671a(29) =718