# A078820 (b-file synthesized from sequence entry) 0 5 1 24 2 100 3 400 4 1575 5 6160 6 24024 7 93600 8 364650 9 1421200 10 5542680 11 21633248 12 84504875 13 330372000 14 1292646000 15 5061729600 16 19835652870 17 77786874000 18 305254551000 19 1198665468000 20 4709756401350 21 18516070880736 22 72834194898000 23 286645366072000 24 1128666128908500