a(n) = (n+1)*(2*n+1)*(3*n+1)*(4*n+1).

Terms

a(0) =1a(1) =120a(2) =945a(3) =3640a(4) =9945a(5) =22176a(6) =43225a(7) =76560a(8) =126225a(9) =196840a(10) =293601a(11) =422280a(12) =589225a(13) =801360a(14) =1066185a(15) =1391776a(16) =1786785a(17) =2260440a(18) =2822545a(19) =3483480a(20) =4254201a(21) =5146240a(22) =6171705a(23) =7343280a(24) =8674225a(25) =10178376a(26) =11870145a(27) =13764520a(28) =15877065a(29) =18223920