# A059420 (b-file synthesized from sequence entry) 1 1 2 20 3 616 4 28160 5 1805056 6 154918400 7 17171485696 8 2389096202240 9 407776690241536 10 83793407533383680 11 20407552701432856576 12 5813146553630295326720 13 1914890082050142493474816