# A121134 (b-file synthesized from sequence entry) 2 1 3 2 4 5 5 11 6 30 7 72 8 182 9 434 10 1048 11 2456 12 5752 13 13240 14 30336 15 68736 16 154912 17 346400 18 770688 19 1704576 20 3753344 21 8226176 22 17959936 23 39062528 24 84679168 25 182983168 26 394278912 27 847263744 28 1816164352 29 3883956224 30 8288010240 31 17649696768