a(n) = 2*(3 + 2 n + 3 n^2 + 3 n^3 + 3 n^4 + n^5 + n^6).

Terms

a(0) =6a(1) =32a(2) =374a(3) =2664a(4) =12278a(5) =42176a(6) =118182a(7) =285704a(8) =617894a(9) =1225248a(10) =2266646a(11) =3961832a(12) =6605334a(13) =10581824a(14) =16382918a(15) =24625416a(16) =36070982a(17) =51647264a(18) =72470454a(19) =99869288a(20) =135410486a(21) =180925632a(22) =238539494a(23) =310699784a(24) =400208358a(25) =510253856a(26) =644445782a(27) =806850024a(28) =1002025814a(29) =1235064128