393044

Appears in sequences

• Number of permutations of length n which avoid the patterns 123, 3241.at n=17A116702
• a(n) = 3*a(n-1) - 4*a(n-2) + 6*a(n-3) - 4*a(n-4), with initial terms 0,1,2,4.at n=19A136427