# A147420 (b-file synthesized from sequence entry) 1 1 2 1 3 1 4 1 5 1 6 9 7 23 8 64 9 295 10 1072 11 4637 12 27060 13 195073 14 1617157 15 15822995 16 190207942 17 2553434864 18 40752029560