# A149344 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 12 4 42 5 144 6 558 7 2115 8 8365 9 32835 10 134882 11 549528 12 2286600 13 9483263 14 40231902 15 170084068 16 727936899 17 3111265619 18 13473412479 19 58262030565 20 253926141635 21 1106269232727 22 4859865964520 23 21339504293971 24 94204444105176 25 415914724112337 26 1846601894388353 27 8198945952462282