# A374658 (b-file synthesized from sequence entry) 0 5 1 20 2 120 3 840 4 8400 5 117600 6 2469600 7 79027200 8 3951360000 9 312157440000 10 39331837440000 11 7945031162880000 12 2582135127936000000 13 1353038807038464000000 14 1144670830754540544000000 15 1564765025641456923648000000 16 3458130706667619801262080000000