cp's OEIS Frontend

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.

A373579 Irregular triangle read by rows where row n lists (in increasing order) the elements of the strong Schreier set encoded by A371176(2*n).

Original entry on oeis.org

2, 3, 4, 3, 4, 5, 3, 5, 4, 5, 6, 3, 6, 4, 6, 5, 6, 4, 5, 6, 7, 3, 7, 4, 7, 5, 7, 4, 5, 7, 6, 7, 4, 6, 7, 5, 6, 7, 8, 3, 8, 4, 8, 5, 8, 4, 5, 8, 6, 8, 4, 6, 8, 5, 6, 8, 7, 8, 4, 7, 8, 5, 7, 8, 6, 7, 8, 5, 6, 7, 8, 9, 3, 9, 4, 9, 5, 9, 4, 5, 9, 6, 9, 4, 6, 9, 5, 6, 9
Offset: 1

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Author

Paolo Xausa, Jun 10 2024

Keywords

Comments

See A373557 (where elements in each set are listed in decreasing order) for more information.

Examples

			Triangle begins:
                                        Corresponding
   n  A371176(2*n)  bin(A371176(2*n))   strong Schreier set
                                        (this sequence)
  ---------------------------------------------------------
   1        2               10          {2}
   2        4              100          {3}
   3        8             1000          {4}
   4       12             1100          {3, 4}
   5       16            10000          {5}
   6       20            10100          {3, 5}
   7       24            11000          {4, 5}
   8       32           100000          {6}
   9       36           100100          {3, 6}
  10       40           101000          {4, 6}
  11       48           110000          {5, 6}
  12       56           111000          {4, 5, 6}
  ...
		

Crossrefs

Subsequence of A373359.
Cf. A007895 (conjectured row lengths), A371176, A373557, A373558, A373853 (row sums).

Programs

  • Mathematica
    Join[{{2}}, Map[PositionIndex[Reverse[IntegerDigits[#, 2]]][1] &, Select[Range[4, 400, 4], DigitCount[#, 2, 1] < IntegerExponent[#, 2] + 1 &]]]

Formula

T(n,k) = A373359(n,k) + 1.