Number of cubic residues mod 9^n.

Terms

a(0) =1a(1) =3a(2) =21a(3) =169a(4) =1515a(5) =13629a(6) =122641a(7) =1103763a(8) =9933861a(9) =89404729a(10) =804642555a(11) =7241782989a(12) =65176046881a(13) =586584421923