Search: id:A065494 Results 1-1 of 1 results found. %I A065494 %S A065494 1,2,4,8,15,30,57,112,216,420,815,1580,3069,5950,11552,22408,43487, %T A065494 84378,163725,317700,616444,1196172,2321007,4503704,8738921,16956954, %U A065494 32903164,63845000,123884479,240384374,466440273,905077080,1756205088 %N A065494 Number of (binary) bit strings in which no even length block of 0's is followed by an even length block of 1's. %F A065494 O.g.f.: (1+x)^2/(1-3x^2-2x^3+x^4) %e A065494 a(6)=64-7=57 because 000011, 001111, 001100, 001101, 100110, 010011, 110011 are forbidden. %Y A065494 Cf. A061279 (forbids odd block 0's - odd block 1's), A065455, A065495, A065497. %Y A065494 Sequence in context: A026023 A077596 A091865 this_sequence A134044 A079967 A018088 %Y A065494 Adjacent sequences: A065491 A065492 A065493 this_sequence A065495 A065496 A065497 %K A065494 nonn %O A065494 0,2 %A A065494 Len Smiley (smiley(AT)math.uaa.alaska.edu), Nov 24 2001 Search completed in 0.001 seconds