# A024954 (b-file synthesized from sequence entry) 1 1 2 1 3 7 4 13 5 19 6 61 7 145 8 301 9 745 10 1729 11 4915 12 11737 13 28675 14 73945 15 200545 16 513265 17 1272385 18 3303745 19 8918911 20 23137501 21 59225587 22 155387413 23 420267097 24 1104554845 25 2876555737 26 7574538529 27 20668692859 28 54731279065 29 143892912259 30 383051857489