# A138775 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 4 9 1 10 10 11 1 12 20 13 1 14 35 15 1 16 56 17 1 18 1 19 84 20 7 21 1 22 120 23 28 24 1 25 165 26 84 27 1 28 220 29 210 30 1 31 286 32 462 33 1 34 1 35 364 36 924 37 10 38 1 39 455 40 1716 41 55 42 1 43 560 44 3003 45 220 46 1 47 680 48 5005 49 715 50 1 51 816 52 8008 53 2002 54 1