546400domain: NAppears in sequencesTriangle T(n,k), n >= 2, 0 <= k <= floor(n^2/2)-n, read by rows, where T(n,k) is the number of 2*(k+n)-cycles in the n X n grid graph which pass through NW and SW corners.at n=36A333652a(n) = Sum_{k=0..floor(2*n/3)} (k+1) * binomial(k,2*n-3*k).at n=29A392267