a(n)=(19^n - 1)/(9*2^(3 - 2*Mod[n, 2])).

A152438

a(n)=(19^n - 1)/(9*2^(3 - 2*Mod[n, 2])).

Terms

    a(0) =0a(1) =1a(2) =5a(3) =381a(4) =1810a(5) =137561a(6) =653415a(7) =49659541a(8) =235882820a(9) =17927094321a(10) =85153698025

External references