a(n) = spt(13n+6)/13 where spt(n) = A092269(n).

A220513

a(n) = spt(13n+6)/13 where spt(n) = A092269(n).

Terms

    a(0) =2a(1) =140a(2) =3042a(3) =38054a(4) =344212a(5) =2488260a(6) =15235620a(7) =81926240a(8) =396603536a(9) =1759312286a(10) =7246532360a(11) =27998586490a(12) =102294344881a(13) =355704104008

External references