# A045993 (b-file synthesized from sequence entry) 0 1 1 9 2 72 3 566 4 4436 5 34748 6 272160 7 2131624 8 16695344 9 130761488 10 1024151680 11 8021372768 12 62825089344 13 492059397056 14 3853913344512 15 30184665012864 16 236412685103872 17 1851634187563264 18 14502390863865856 19 113585794743350784