2117520domain: NAppears in sequencesNumber of permutations (p1,...,pn) such that 1 <= |pk - k| <= 2 for all k.at n=25A033305Number of permutations of [n] with no fixed points where the maximal displacement of an element equals two.at n=23A321048Expansion of e.g.f. 1/(1 - x^3 * (exp(x) - 1)).at n=10A358014