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A362063
Number of 2-balanced binary words of length n with respect to the permutations of the symbols.
1
1, 1, 2, 4, 8, 16, 31, 60, 111, 205, 364, 647, 1110, 1908, 3190, 5345, 8743, 14352, 23090, 37232, 59113, 94079, 147531, 232073, 360750, 561692, 865823, 1338269, 2047388, 3139690, 4781349, 7281656, 11021651, 16716751, 25178531, 37994309, 57046272
OFFSET
0,3
COMMENTS
2-balanced binary words are here defined as the binary words with such property that the sum of each subblock differs by at most 2 from every other subblock of the same length.
Can be interpreted as a number of 2-balanced binary words with the prefix "0".
FORMULA
a(n) = A274005(n)/2 for n>0, since A274005 is the number of all binary 2-balanced words of given length.
EXAMPLE
a(3) = 4 since 000, 001, 010 and 011 are 2-balanced.
a(6) = 31 since all words of form 0XXXXX are 2-balanced, except the word 000111.
CROSSREFS
A274005 is the number of all binary 2-balanced words with given length.
A005598 is the number of all binary balanced (1-balanced) words with given length.
Sequence in context: A334636 A299026 A007800 * A309982 A102726 A188900
KEYWORD
nonn
AUTHOR
Dominika Datko, communicated by Bartlomiej Pawlik, Apr 07 2023
STATUS
approved