# A045631 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 20 5 70 6 243 7 889 8 3276 9 12276 10 46435 11 176869 12 677022 13 2602197 14 10033212 15 38787495 16 150286400 17 583434322 18 2268848988 19 8836447021 20 34461894010 21 134564992002 22 526025788992 23 2058359779051 24 8061905110548 25 31602659997975