# A001241 (b-file synthesized from sequence entry) 1 1 2 50 3 1660 4 46760 5 1217776 6 30480800 7 747497920 8 18139003520 9 437786795776 10 10536798272000 11 253246254177280 12 6082300519393280 13 146028165842661376 14 3505313580591718400 15 84135194495708938240 16 2019336829962040279040