# A162925 (b-file synthesized from sequence entry) 0 1 1 5 2 20 3 80 4 310 5 1200 6 4650 7 18000 8 69690 9 269820 10 1044630 11 4044420 12 15658470 13 60623640 14 234711810 15 908715240 16 3518201250 17 13621143060 18 52735907790 19 204173464860 20 790482339630 21 3060448278480 22 11848896802170 23 45874441471680