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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.

A129265 Triangle read by rows: T(n,k) is the number of power of two divisors of n that are less than or equal to n/k.

Original entry on oeis.org

1, 2, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1

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Author

Gary W. Adamson, Apr 06 2007

Keywords

Comments

Equals A115361 * A000012 as infinite lower triangular matrices (cf. A129264).

Examples

			First few rows of the triangle are:
  1;
  2, 1;
  1, 1, 1;
  3, 2, 1, 1;
  1, 1, 1, 1, 1;
  2, 2, 2, 1, 1, 1;
  1, 1, 1, 1, 1, 1, 1;
  ...
		

Crossrefs

Row sums are A129527.
Column 1 is A001511.

Programs

  • PARI
    T(n, k)={sumdiv(n, d, d <= n/k && d==1<Andrew Howroyd, Aug 07 2018

Formula

T(n,k) = 1 for n odd.

Extensions

Name changed and terms a(56) and beyond from Andrew Howroyd, Aug 07 2018