17575724491domain: NAppears in sequencesa(n) equals the coefficient of x^n in Sum_{m>=0} (x^m + 5 + 1/x^m)^m for n >= 1.at n=12A316595a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+1,k+1) * binomial(2*k+2,k+2).at n=12A387278