a(n) = (4*n+9)*n^2.

Terms

a(0) =0a(1) =13a(2) =68a(3) =189a(4) =400a(5) =725a(6) =1188a(7) =1813a(8) =2624a(9) =3645a(10) =4900a(11) =6413a(12) =8208a(13) =10309a(14) =12740a(15) =15525a(16) =18688a(17) =22253a(18) =26244a(19) =30685a(20) =35600a(21) =41013a(22) =46948a(23) =53429a(24) =60480a(25) =68125a(26) =76388a(27) =85293a(28) =94864a(29) =105125