# A321521 (b-file synthesized from sequence entry) 1 1 2 1 3 7 4 21 5 121 6 715 7 5041 8 40293 9 362887 10 3628681 11 39916801 12 479000895 13 6227020801 14 87178286161 15 1307674368127 16 20922789847653 17 355687428096001 18 6402373705365835 19 121645100408832001 20 2432902008173011101 21 51090942171709445047 22 1124000727777567763201