150536domain: NAppears in sequencesGeneralized Stirling numbers, [n+2,n]_2.at n=31A001701Number of (3+1)X(n+1) arrays of permutations of 0..n*4+3 with each element having directed index change -1,1 -1,2 1,0 or 0,-1.at n=9A264552a(n) = n*((2+sqrt(3))^n + (2-sqrt(3))^n)/2.at n=8A278417