# A000646 (b-file synthesized from sequence entry) 0 1 1 2 2 3 3 6 4 13 5 28 6 62 7 144 8 338 9 810 10 1970 11 4852 12 12073 13 30334 14 76805 15 195850 16 502461 17 1296122 18 3359527 19 8745744 20 22856223 21 59944156 22 157718380 23 416189954 24 1101204387 25 2920914484 26 7765357967 27 20688204244 28 55225188289 29 147688302518