# A052606 (b-file synthesized from sequence entry) 0 1 1 2 2 16 3 180 4 2688 5 50160 6 1123200 7 29342880 8 876072960 9 29425939200 10 1098191001600 11 45083550758400 12 2019049224192000 13 97957525739673600 14 5118154482618777600 15 286518188551795200000 16 17108806991486386176000