# A221176 (b-file synthesized from sequence entry) 0 1 1 16 2 272 3 4880 4 91920 5 1810192 6 37142288 7 791744272 8 17490370320 9 399558315792 10 9421351690000 11 228916588400400 12 5723078052339472 13 147025755978698512 14 3876566243300318992 15 104789417805394595600 16 2901159958960121863952 17 82188946843192555474704 18 2380551266738846355103504 19 70441182699006212824911632