Convolution of A023532 and A001950.

Terms

a(0) =2a(1) =5a(2) =9a(3) =17a(4) =25a(5) =34a(6) =48a(7) =62a(8) =78a(9) =96a(10) =116a(11) =140a(12) =165a(13) =191a(14) =220a(15) =251a(16) =284a(17) =320a(18) =359a(19) =399a(20) =439a(21) =484a(22) =530a(23) =579a(24) =632a(25) =685a(26) =741a(27) =798a(28) =858a(29) =920