# A276734 (b-file synthesized from sequence entry) 1 1 2 5 3 7 4 9 5 21 6 22 7 44 8 45 9 66 10 70 11 78 12 112 13 150 14 156 15 160 16 264 17 270 18 280 19 432 20 600 21 1080 22 1680