516240domain: NAppears in sequencesTheta series of 10-dimensional integral lattice O_10.at n=29A306434a(n) = n! * Sum_{k=0..floor(n/2)} 1/binomial(n-k, k).at n=9A358446Array read by antidiagonals: T(n,k) is the number of k-tuples of permutations of [n] that pairwise commute.at n=61A362827