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

Terms

a(0) =5a(1) =255a(2) =3145a(3) =16835a(4) =59085a(5) =161095a(6) =371345a(7) =759435a(8) =1419925a(9) =2476175a(10) =4084185a(11) =6436435a(12) =9765725a(13) =14349015a(14) =20511265a(15) =28629275a(16) =39135525a(17) =52522015a(18) =69344105a(19) =90224355a(20) =115856365a(21) =147008615a(22) =184528305a(23) =229345195a(24) =282475445a(25) =345025455a(26) =418195705a(27) =503284595a(28) =601692285