a(n) = denominator(3*(3+(-1)^n)/(n+1)^3).

Terms

a(0) =1a(1) =4a(2) =9a(3) =32a(4) =125a(5) =36a(6) =343a(7) =256a(8) =243a(9) =500a(10) =1331a(11) =288a(12) =2197a(13) =1372a(14) =1125a(15) =2048a(16) =4913a(17) =972a(18) =6859a(19) =4000a(20) =3087a(21) =5324a(22) =12167a(23) =2304a(24) =15625a(25) =8788a(26) =6561a(27) =10976a(28) =24389a(29) =4500