# A117615 (b-file synthesized from sequence entry) 0 0 1 1 2 4 3 18 4 72 5 290 6 1160 7 4642 8 18568 9 74274 10 297096 11 1188386 12 4753544 13 19014178 14 76056712 15 304226850 16 1216907400 17 4867629602 18 19470518408 19 77882073634 20 311528294536 21 1246113178146 22 4984452712584 23 19937810850338 24 79751243401352