55458domain: NAppears in sequencesa(n) = n*(n + 1)*(3*n + 1).at n=26A027903Engel expansion of sinh(1/3).at n=39A068380Numbers k such that k!!!!!! + 1 is prime.at n=48A085150Triangular array formed by the little Schröder numbers s(n,k).at n=49A110440Nonnegative k such that 3*k + 1 is a perfect cube.at n=18A121628