# A056497 (b-file synthesized from sequence entry) 1 6 2 15 3 30 4 105 5 210 6 705 7 1290 8 4410 9 7740 10 26985 11 46650 12 162435 13 279930 14 978465 15 1679370 16 5874120 17 10077690 18 35263440 19 60466170 20 211604295 21 362795730 22 1269743025 23 2176782330 24 7618570470 25 13060693800