# A056550 (b-file synthesized from sequence entry) 1 1 2 2 3 8 4 11 5 17 6 63 7 180 8 259 9 818 10 2161 11 4441 12 8305 13 11998 14 694218 15 3447076 16 4393603 17 57402883 18 73459800 19 121475393 20 2068420025 21 5577330586 22 13320495021 23 35297649260 24 138630178659 25 988671518737