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.

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

1,2

Comments

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

Links

Andrew Howroyd, Table of n, a(n) for n = 1..1275

Formula

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

Example

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;
  ...

Prog

(PARI) T(n, k)={sumdiv(n, d, d <= n/k && d==1<<valuation(d, 2))} \\ Andrew Howroyd, Aug 07 2018

Crossrefs

Row sums are A129527.

Column 1 is A001511.

Cf. A115361, A000012, A129264.

Sequence in context: A334055 A365838 A254613 * A030358 A118914 A135063

Adjacent sequences: A129262 A129263 A129264 * A129266 A129267 A129268

Keyword

nonn,tabl

Author

Gary W. Adamson, Apr 06 2007

Extensions

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

Status

approved