# A027140 (b-file synthesized from sequence entry) 0 1 1 3 2 12 3 57 4 264 5 1261 6 6141 7 30276 8 150853 9 758145 10 3836896 11 19534086 12 99957904 13 513756551 14 2650822585 15 13724435509 16 71275344341 17 371177285715 18 1937791196448 19 10139548682524 20 53165765660928 21 279301910804937