a(n) = (7*n + 3)^5.

Terms

a(0) =243a(1) =100000a(2) =1419857a(3) =7962624a(4) =28629151a(5) =79235168a(6) =184528125a(7) =380204032a(8) =714924299a(9) =1252332576a(10) =2073071593a(11) =3276800000a(12) =4984209207a(13) =7339040224a(14) =10510100501a(15) =14693280768a(16) =20113571875a(17) =27027081632a(18) =35723051649a(19) =46525874176