a(n) = 12^(2n+1) + 6 * 12^n + 1: the right Aurifeuillian factor of 12^(6n+3) + 1.

A220990

a(n) = 12^(2n+1) + 6 * 12^n + 1: the right Aurifeuillian factor of 12^(6n+3) + 1.

Terms

    a(0) =19a(1) =1801a(2) =249697a(3) =35842177a(4) =5159904769a(5) =743009863681

External references