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.

A267584 a(0)=1; thereafter a(n) = 2^(1 + number of zeros in binary expansion of n).

Original entry on oeis.org

1, 2, 4, 2, 8, 4, 4, 2, 16, 8, 8, 4, 8, 4, 4, 2, 32, 16, 16, 8, 16, 8, 8, 4, 16, 8, 8, 4, 8, 4, 4, 2, 64, 32, 32, 16, 32, 16, 16, 8, 32, 16, 16, 8, 16, 8, 8, 4, 32, 16, 16, 8, 16, 8, 8, 4, 16, 8, 8, 4, 8, 4, 4, 2, 128, 64, 64, 32, 64, 32, 32, 16, 64
Offset: 0

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Author

N. J. A. Sloane, Jan 17 2016

Keywords

Examples

			12 = 1100 in binary, which contains two 0's, so a(12) = 2^3 = 8.
		

Crossrefs

Partial sums give A064194.
Cf. A023416.

Programs

  • Mathematica
    Join[{1},Table[2^(1+DigitCount[n,2,0]),{n,80}]] (* Harvey P. Dale, Oct 08 2023 *)

Formula

For n >= 1, a(n) = 2^(1+A023416(n)).