388727domain: NPropertiesPrimalityPrimeyesAppears in sequencesThe number of permutations of length n in a particular geometric grid class.at n=13A226433Solution of the complementary equation a(n) = a(n-1) + a(n-2) + 2*b(n-1) + 2*b(n-2), where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=21A294419Prime numbersat n=32963