365640

Appears in sequences

• sech(exp(x)-sec(x))=1-1/2!*x^2+1/4!*x^4+20/5!*x^5+23/6!*x^6...at n=11A013339
• Number of consistent sets of 3 irreflexive binary order relationships over n objects.at n=9A147796
• Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, down, down, down.at n=3A177624