# A135920 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 7 4 37 5 264 6 2433 7 27913 8 386906 9 6346119 10 121159373 11 2655174768 12 66028903633 13 1845579100993 14 57506847262162 15 1983312152411351 16 75238783332550789 17 3122408658986242072 18 141063757638078429489