Convolution of A000201 and A014306.

Terms

a(0) =0a(1) =1a(2) =4a(3) =7a(4) =11a(5) =18a(6) =25a(7) =34a(8) =45a(9) =56a(10) =69a(11) =83a(12) =98a(13) =116a(14) =135a(15) =155a(16) =178a(17) =201a(18) =227a(19) =253a(20) =279a(21) =308a(22) =338a(23) =370a(24) =404a(25) =438a(26) =476a(27) =514a(28) =553a(29) =596