# A194130 (b-file synthesized from sequence entry) 1 1 2 2 3 2 4 24 5 120 6 240 7 5040 8 40320 9 120960 10 3628800 11 39916800 12 159667200 13 6227020800 14 87178291200 15 435891456000 16 20922789888000 17 355687428096000 18 2134124568576000 19 121645100408832000 20 2432902008176640000 21 17030314057236480000 22 1124000727777607680000