328426

Appears in sequences

• a(n) is the smallest number k such that k*2^(2^n) + 1 is prime.at n=19A030239
• G.f. satisfies A(x) = 1 + x*(1 + 1/A(x)^3).at n=7A364407
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,0) = 0^n and T(n,k) = k * Sum_{r=0..n} binomial(n,r) * binomial(n+3*r+k,n)/(n+3*r+k) for k > 0.at n=51A378237