# A025937 (b-file synthesized from sequence entry) 0 1 1 18 2 211 3 2052 4 18025 5 148806 6 1179487 7 9089784 8 68647909 9 510709914 10 3756191803 11 27381204396 12 198197187553 13 1426557620142 14 10220981500759 15 72957382445088 16 519164877763357 17 3684933735388290 18 26099214855723955