181657

Appears in sequences

• Number of subsequences of [ 1,...,n ] in which each even number has an odd neighbor.at n=19A007481
• a(n) = 3*a(n-1) + 2*a(n-2), with a(0)=2, a(1)=7.at n=9A007484
• The number of simple permutations of length n in a particular geometric grid class.at n=23A226432