# A090578 (b-file synthesized from sequence entry) 0 1 1 4 2 10 3 30 4 74 5 222 6 546 7 1628 8 3978 9 11810 10 28658 11 84520 12 203562 13 596520 14 1425924 15 4150232 16 9838116 17 28418002 18 66805554