# A049141 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 6 5 20 6 72 7 270 8 1049 9 4176 10 16962 11 69990 12 292608 13 1236718 14 5275724 15 22685636 16 98225447 17 427888458 18 1873979814 19 8246535936 20 36444747110 21 161685649174 22 719819353928 23 3214805630688 24 14399464322254 25 64668729869542