# A123308 (b-file synthesized from sequence entry) 0 1 1 3 2 18 3 144 4 1422 5 16848 6 235458 7 3827628 8 71466174 9 1515031920 10 36091609434 11 957367079244 12 28050237910926 13 901359663633000 14 31567805908329330 15 1198307340146774844 16 49060139971072916142 17 2156816501291429473248