20391

Appears in sequences

• Interprimes (A024675) which are of the form s*prime, s=21.at n=37A075296
• The bisection A053445(2n+1).at n=29A161921
• Number of partitions of n into exactly 6 different parts with distinct multiplicities.at n=23A212117
• Number of triangular number parts in all partitions of n.at n=28A263235
• The number of partitions of n which represent Chomp positions with Sprague-Grundy value 10.at n=58A284784
• Number of closable Motzkin trees.at n=13A300125
• G.f. A(x) satisfies A(x) = 1 + x*A(x)/A(-x*A(x))^2.at n=10A385014
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A385014.at n=76A385018