# A074358 (b-file synthesized from sequence entry) 0 0 1 0 2 0 3 4 4 20 5 80 6 288 7 976 8 3184 9 10112 10 31488 11 96576 12 292672 13 878336 14 2614784 15 7731456 16 22728448 17 66482176 18 193617920 19 561718272 20 1624101888 21 4681535488 22 13457924096 23 38592008192 24 110419341312 25 315287830528 26 898583560192