a(n) = (2*n^6 - 6*n^5 + 5*n^4 - n^2 + 12)/12.

Terms

a(0) =1a(1) =1a(2) =2a(3) =34a(4) =277a(5) =1301a(6) =4426a(7) =12202a(8) =29009a(9) =61777a(10) =120826a(11) =220826a(12) =381877a(13) =630709a(14) =1002002a(15) =1539826a(16) =2299201a(17) =3347777a(18) =4767634a(19) =6657202a(20) =9133301a(21) =12333301a(22) =16417402a(23) =21571034a(24) =28007377a(25) =35970001a(26) =45735626a(27) =57617002a(28) =71965909a(29) =89176277