125706

Appears in sequences

• Numbers k such that 3*R_k + 50 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=23A256800
• G.f. A(x) satisfies: [x^n] A(x)^(n+1) = [x^n] (1 + x*A(x)^(3*n+1))^(n+1) for n >= 0.at n=5A360337