# A180666 (b-file synthesized from sequence entry) 0 0 1 1 2 2 3 6 4 15 5 41 6 106 7 279 8 729 9 1911 10 5001 11 13095 12 34281 13 89752 14 234971 15 615165 16 1610520 17 4216400 18 11038675 19 28899630 20 75660210 21 198081006 22 518582802 23 1357667406 24 3554419410 25 9305590831 26 24362353076 27 63781468404