# A336734 (b-file synthesized from sequence entry) 0 0 1 1 2 57 3 1071 4 12279 5 106738 6 781458 7 5111986 8 30980370 9 178047831 10 985621119 11 5311715977 12 28075774881 13 146309927344 14 754544640000 15 3861338821620 16 19646614600164 17 99532074868285 18 502608221035605 19 2531829420822835 20 12730273358124315 21 63919766245452606