499680domain: NAppears in sequencesa(n) = Sum_{k = 0..3} (n+k)! C(3,k).at n=7A001345Square array A(row,col) = Sum_{k=0..row} binomial(row,k)*(1+col+k)!, read by descending antidiagonals as A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), ...at n=39A276588Transpose of A276588.at n=41A276589