230731

Appears in sequences

• Numbers k such that 3^8*2^k - 1 is prime.at n=20A212311
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(Sum_{j>=1} sigma_k(j) * x^j).at n=42A294296
• E.g.f.: exp(Sum_{n>=1} sigma_2(n) * x^n).at n=6A294362