59246

Appears in sequences

• Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down.at n=4A177556
• Number of 2n-step lattice paths from (0,0) to (0,0) using steps in {N, S, E, W} starting with East, then always moving straight ahead or turning left.at n=11A228248
• a(1) = 1; a(n+1) = Sum_{k=1..n} a(k) * ceiling(n/k).at n=13A332846