28446

Appears in sequences

• Number of permutations of length n which avoid the patterns 231, 1423, 3214.at n=17A116717
• Number of 0..2 arrays of length n+3 with sum no more than 4 in any length 4 subsequence (=50% duty cycle).at n=7A212226
• Triangle read by rows: T(n,k) is the number of simple series-parallel matroids on [n] with rank k, 1 <= k <= n.at n=63A361355