80004domain: NAppears in sequencesG.f. satisfies: A(x) = Sum_{n>=0} x^n / Product_{k=1..n} (x + A(-x)^k).at n=15A221835Number of n X 2 binary arrays whose sum with another n X 2 binary array containing no more than a single 1 has rows and columns in lexicographically nondecreasing order.at n=25A225894