# A048681 (b-file synthesized from sequence entry) 1 1 2 2 3 3 4 6 5 10 6 15 7 35 8 70 9 42 10 210 11 462 12 462 13 858 14 3003 15 5005 16 4290 17 24310 18 24310 19 92378 20 125970 21 293930 22 646646 23 1352078 24 1352078 25 817190 26 5311735 27 2897310 28 13123110 29 34597290 30 17298645 31 100180065 32 200360130 33 129644790 34 2203961430