# A049138 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 6 5 20 6 70 7 254 8 947 9 3604 10 13936 11 54574 12 215914 13 861454 14 3461208 15 13988932 16 56821743 17 231793334 18 949033702 19 3897956648 20 16053912116 21 66275614190 22 274168532480 23 1136192222288 24 4715741791756 25 19598263084654