a(n) = (2*n+1)^5.

Terms

a(0) =1a(1) =243a(2) =3125a(3) =16807a(4) =59049a(5) =161051a(6) =371293a(7) =759375a(8) =1419857a(9) =2476099a(10) =4084101a(11) =6436343a(12) =9765625a(13) =14348907a(14) =20511149a(15) =28629151a(16) =39135393a(17) =52521875a(18) =69343957a(19) =90224199a(20) =115856201a(21) =147008443a(22) =184528125a(23) =229345007a(24) =282475249a(25) =345025251a(26) =418195493a(27) =503284375a(28) =601692057