Squares of second pentagonal numbers: a(n) = (1/4)*n^2*(3*n+1)^2.

Terms

a(0) =0a(1) =4a(2) =49a(3) =225a(4) =676a(5) =1600a(6) =3249a(7) =5929a(8) =10000a(9) =15876a(10) =24025a(11) =34969a(12) =49284a(13) =67600a(14) =90601a(15) =119025a(16) =153664a(17) =195364a(18) =245025a(19) =303601a(20) =372100a(21) =451584a(22) =543169a(23) =648025a(24) =767376a(25) =902500a(26) =1054729a(27) =1225449a(28) =1416100a(29) =1628176