68185domain: NAppears in sequencesa(n) is the positive integer x such that 3^((M-1)/(2*p)) == -2^x (mod M), where p > 2 is prime, M=2^p-1 is the n-th Mersenne prime and x < p.at n=26A278792Triangle read by rows: T(n,k) = (Sum_{i=k..n} i!)/(k!) for 0 <= k <= n.at n=48A348482