# A000638 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 11 5 19 6 56 7 96 8 296 9 554 10 1593 11 3094 12 10723 13 20832 14 75154 15 159129 16 686165 17 1466358 18 7274651