# A012480 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 -1 4 -7 5 -15 6 25 7 359 8 1297 9 3713 10 785 11 347151 12 3237577 13 62839153 14 476552297 15 10196506423 16 93536269473 17 2397571040897 18 25410713978785 19 714196911010335 20 8498142387238425 21 263318643848985457