Nearest integer to n^6/36.

Terms

a(0) =0a(1) =2a(2) =20a(3) =114a(4) =434a(5) =1296a(6) =3268a(7) =7282a(8) =14762a(9) =27778a(10) =49210a(11) =82944a(12) =134078a(13) =209154a(14) =316406a(15) =466034a(16) =670488a(17) =944784a(18) =1306830a(19) =1777778a(20) =2382392a(21) =3149442a(22) =4112108a(23) =5308416a(24) =6781684a(25) =8580994a(26) =10761680a(27) =13385842a(28) =16522870a(29) =20250000