# A009237 (b-file synthesized from sequence entry) 0 1 1 1 2 0 3 2 4 -4 5 26 6 -134 7 930 8 -6728 9 53056 10 -413744 11 2752936 12 -3042040 13 -488089848 14 16658828096 15 -442856699584 16 11075864697536 17 -274957302952960 18 6922538197811392 19 -178529204224920384 20 4739350807332125056