# A009523 (b-file synthesized from sequence entry) 0 1 1 -6 2 72 3 -1848 4 81088 5 -5318016 6 483162240 7 -57865303296 8 8815813734400 9 -1662921003208704 10 380141599264751616 11 -103492751953073897472 12 33072262407957372633088 13 -12253967233389523820544000