# A019578 (b-file synthesized from sequence entry) 3 1 4 12 5 160 6 2450 7 43050 8 858480 9 19208000 10 477237600 11 13049190000 12 389642022000 13 12620614406400 14 440871877446000 15 16525943429595600 16 661779275661504000 17 28199857953915648000 18 1274233240573028736000 19 60863881753459328544000