Convolution of nonzero squares A000290 with themselves.

Terms

a(0) =1a(1) =8a(2) =34a(3) =104a(4) =259a(5) =560a(6) =1092a(7) =1968a(8) =3333a(9) =5368a(10) =8294a(11) =12376a(12) =17927a(13) =25312a(14) =34952a(15) =47328a(16) =62985a(17) =82536a(18) =106666a(19) =136136a(20) =171787a(21) =214544a(22) =265420a(23) =325520a(24) =396045a(25) =478296a(26) =573678a(27) =683704a(28) =809999a(29) =954304