3872000domain: NAppears in sequencesPseudo-factorials: a(0)=1, a(n+1) = (-1)^(n+1) * Sum_{k=0..n} binomial(n,k) * a(k)*a(n-k), n>=0.at n=11A098777Number of length n binary sequences with at most 3 of every 6 adjacent bits set.at n=26A133551