# A134968 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 16 4 54 5 168 6 462 7 1212 8 2937 9 6832 10 15135 11 32430 12 66898 13 134710 14 263466 15 504308 16 944208 17 1736575 18 3134832 19 5574947 20 9760954 21 16868418 22 28771587 23 48513127 24 80867486 25 133455462 26 218041708 27 353039664 28 566580113 29 901958971 30 1424480451 31 2233367056