# A176720 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 8 4 18 5 44 6 112 7 288 8 744 9 1938 10 5104 11 13584 12 36456 13 98468 14 267376 15 729488 16 1999074 17 5500412 18 15189636 19 42084952 20 116949848 21 325878288 22 910333152 23 2548892864 24 7152113760 25 20108587038 26 56641227416 27 159820928328