# A259815 (b-file synthesized from sequence entry) 1 4 2 16 3 68 4 232 5 796 6 2528 7 8036 8 24520 9 74796 10 222400 11 660868 12 1929944 13 5631748 14 16228768 15 46730860 16 133288872 17 379917092 18 1074853312 19 3039122932 20 8541661232 21 23994293596 22 67070070848 23 187391828604