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.

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A291555 Number of even numbers less than 10^n that contain their greatest odd factor as a substring.

Original entry on oeis.org

0, 1, 4, 15, 40, 57, 76, 108, 146, 194, 258, 336, 447, 544, 663, 807, 970, 1132, 1333, 1567
Offset: 1

Views

Author

Bobby Jacobs and Robert G. Wilson v, Aug 26 2017

Keywords

Comments

The number of terms of A291460 less than 10^n.
2^10*x = 1024*x contains x for all x from 1 to 41. Therefore, most of the terms in A291460 less than 10^5 are of the form 1024*x for odd x from 1 to 41.

Examples

			There are 4 numbers in A291460 less than 10^3 = 1000 (16, 128, 384, 512). Therefore, a(3) = 4.

Crossrefs

Cf. A000265, A291460.

Extensions

a(14)-a(20) from Giovanni Resta, Aug 31 2017
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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