344160

Appears in sequences

• Numbers k such that the sets of prime factors (ignoring multiplicity) of A000203(k) = sigma(k) and of A001157(k) = sigma_2(k) are identical.at n=13A081380
• Triangle read by rows: T(n,k) is the number of weighted lattice paths in B(n) having k ascents. The members of B(n) are paths of weight n that start at (0,0), end on but never go below the horizontal axis, and whose steps are of the following four kinds: an (1,0)-step with weight 1, an (1,0)-step with weight 2, a (1,1)-step with weight 2, and a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps. An ascent is a maximal sequence of consecutive (1,1)-steps.at n=66A246186
• p-INVERT of (0,1,0,1,0,1,...), where p(S) = (1 - S^3)^2.at n=26A291240