Convolution of nonzero pentagonal numbers (A000326) with themselves.

Terms

a(0) =1a(1) =10a(2) =49a(3) =164a(4) =434a(5) =980a(6) =1974a(7) =3648a(8) =6303a(9) =10318a(10) =16159a(11) =24388a(12) =35672a(13) =50792a(14) =70652a(15) =96288a(16) =128877a(17) =169746a(18) =220381a(19) =282436a(20) =357742a(21) =448316a(22) =556370a(23) =684320a(24) =834795a(25) =1010646a(26) =1214955a(27) =1451044a(28) =1722484a(29) =2033104