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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A365746 Table read by antidiagonals upward: T(n,k) is the number of binary strings of length k with the property that every substring of length A070939(n) is lexicographically earlier than the binary expansion of n; n, k >= 0.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 2, 2, 1, 0, 1, 2, 3, 2, 1, 0, 1, 2, 4, 5, 2, 1, 0, 1, 2, 4, 4, 8, 2, 1, 0, 1, 2, 4, 5, 4, 13, 2, 1, 0, 1, 2, 4, 6, 7, 4, 21, 2, 1, 0, 1, 2, 4, 7, 10, 11, 4, 34, 2, 1, 0, 1, 2, 4, 8, 13, 16, 16, 4, 55, 2, 1, 0, 1, 2, 4, 8, 8, 24
Offset: 0

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Author

Peter Kagey, Sep 17 2023

Keywords

Examples

			Table begins:
 n\k | 0  1  2  3   4   5   6   7    8    9   10   11
-----+----------------------------------------------------
   0 | 1, 0, 0, 0,  0,  0,  0,  0,   0,   0,   0,   0, ...
   1 | 1, 1, 1, 1,  1,  1,  1,  1,   1,   1,   1,   1, ...
   2 | 1, 2, 2, 2,  2,  2,  2,  2,   2,   2,   2,   2, ...
   3 | 1, 2, 3, 5,  8, 13, 21, 34,  55,  89, 144, 233, ...
   4 | 1, 2, 4, 4,  4,  4,  4,  4,   4,   4,   4,   4, ...
   5 | 1, 2, 4, 5,  7, 11, 16, 23,  34,  50,  73, 107, ...
   6 | 1, 2, 4, 6, 10, 16, 26, 42,  68, 110, 178, 288, ...
   7 | 1, 2, 4, 7, 13, 24, 44, 81, 149, 274, 504, 927, ...
   8 | 1, 2, 4, 8,  8,  8,  8,  8,   8,   8,   8,   8, ...
   9 | 1, 2, 4, 8,  9, 11, 15, 23,  32,  43,  58,  81, ...
For (n,k) = (3,4), we see that T(3,4) = 8 because there are 8 binary strings of length k = 4 where all length A070939(3) = 2 substrings are lexicographically earlier than "11" (the binary expansion of n = 3): 0000, 0001, 0010, 0100, 0101, 1000, 1001, and 1010.
		

Crossrefs

Cf. A000045 (row 3), A164316 (row 5), A128588 (row 6), A000073 (row 7).

Programs

  • Mathematica
    A365746Row[s_,
      numberOfTerms_] := (digits = If[s == 0, 1, Ceiling[Log[2, s + 1]]];
      m = 2^(digits - 1);
      transferMatrix =
       If[s == 0, {{0}},
        Table[If[(Ceiling[i/2] ==
             j) || ((i <= s - m) && (Ceiling[i/2] == j - m/2)), 1, 0], {i,
           1, m}, {j, 1, m}]];
      sequence =
       Table[2^k, {k, 0, digits - 1}] ~Join~
        Table[MatrixPower[transferMatrix, k] // Total // Total, {k, 1,
          numberOfTerms - digits}];
      Take[sequence, numberOfTerms])

Formula

G.f. for row n = 0: 1;
G.f. for row n = 1: 1/(1 - x);
G.f. for row n = 2: (1 + x)/(1 - x);
G.f. for row n = 3: (1 + x)/(1 - x - x^2);
G.f. for row n = 4: (1 + x + 2x^2)/(1 - x);
G.f. for row n = 5: (1 + x + 2x^2)/(1 - x - x^3);
G.f. for row n = 6: (1 + x + x^2)/(1 - x - x^2);
G.f. for row n = 7: (1 + x + x^2)/(1 - x - x^2 - x^3);
G.f. for row n = 8: (1 + x + 2 x^2 + 4 x^3)/(1 - x);
G.f. for row n = 9: (1 + x + 2x^2 + 4x^3)/(1 - x - x^4).