95450domain: NAppears in sequencesNumbers k such that the sum of the first k Catalan numbers, C_1 + C_2 + ... + C_k, is divisible by k.at n=5A133927Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (-1, 1, 1), (1, -1, 0), (1, 0, 1), (1, 1, -1)}.at n=9A149479