# A012725 (b-file synthesized from sequence entry) 0 1 1 2 2 28 3 920 4 54416 5 5056288 6 678865856 7 124425704832 8 29873423298816 9 9104340085891584 10 3435702339713424384 11 1573394503700675106816 12 859935938676055185002496 13 553085284375423405752918016