8731800domain: NAppears in sequencesNumber of permutations of an n-set containing a 4-cycle.at n=11A029571Triangle a(n,k) = binomial(n,k)*binomial(n+1,k+1)*binomial(n+2,k+2) read by rows.at n=50A187552a(n) = Product_{d|n} A019565(d)^(1-A008966(n/d)).at n=71A300830Expansion of e.g.f. 1/(1 - (exp(x) - 1)^5).at n=10A373940