258873

Appears in sequences

• The number of 4321-avoiding separable permutations of length n.at n=12A165521
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) - b(n-1) + 6, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=25A294413