67727domain: NAppears in sequencesDuplicate of A029561.at n=3A028893Quasi-Carmichael numbers to base 2: squarefree composites n such that prime p|n ==> p-2|n-2.at n=3A029561Number of permutations of length n which avoid the patterns 1342, 3421, 4213.at n=10A116802Number of poly-IH68-tiles (holes allowed) with n cells.at n=10A182645