# A148490 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 21 5 75 6 284 7 1109 8 4470 9 18453 10 77433 11 329126 12 1415834 13 6149299 14 26931302 15 118780241 16 527010199 17 2350740211 18 10534962936 19 47408681317 20 214136796301 21 970426128408 22 4410950701961 23 20104046171859 24 91856203336505 25 420644431533937 26 1930293373533896 27 8874862002582146 28 40875930281689623