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

Terms

a(0) =0a(1) =1a(2) =25a(3) =144a(4) =484a(5) =1225a(6) =2601a(7) =4900a(8) =8464a(9) =13689a(10) =21025a(11) =30976a(12) =44100a(13) =61009a(14) =82369a(15) =108900a(16) =141376a(17) =180625a(18) =227529a(19) =283024a(20) =348100a(21) =423801a(22) =511225a(23) =611524a(24) =725904a(25) =855625a(26) =1002001a(27) =1166400a(28) =1350244a(29) =1555009