49111domain: NAppears in sequencesNumbers k such that A109631(k) - A109631(k+1) = A109631(k+2).at n=21A109715Least k such that 10^n + k is a Sophie Germain prime and the lesser of a twin prime pair.at n=23A118580Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = Sum_{d|n} d*sigma_k(d).at n=60A322104