4316928

Appears in sequences

• Integers k such that numerator and denominator of sigma(k)/k are both prime.at n=28A247086
• Number of unordered pairs of self-avoiding paths with nodes that cover all vertices of a convex n-gon.at n=11A332426
• Triangle read by rows: T(n,k) is the number of sets of noncrossing paths of size k that cover n nodes arranged in a circle with one node paths disallowed, 0 <= k <= floor(n/2).at n=44A390893