# A138909 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 33 4 232 5 2045 6 21636 7 267043 8 3766848 9 59776137 10 1053986500 11 20442543671 12 432537117552 13 9914571191005 14 244742376434388 15 6473030199939675 16 182614314495736576 17 5473825396372806545 18 173728330742517310980