# A321574 (b-file synthesized from sequence entry) 0 1 1 4 2 20 3 108 4 604 5 3444 6 19876 7 115644 8 676748 9 3977316 10 23451700 11 138634764 12 821221692 13 4872734676 14 28952250564 15 172222729308 16 1025461169772 17 6110912705220 18 36441840179284 19 217450403367852 20 1298228971572764 21 7754336590794804 22 46335720234364900