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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A063873 Duplicate of A063131.

Original entry on oeis.org

55, 91, 215, 407, 493, 893, 1189, 1343, 1403, 1643, 1681, 1961, 3151, 3223, 3415
Offset: 1

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Author

Keywords

A063127 Composite numbers which in base 2 contain their largest proper factor as a substring.

Original entry on oeis.org

4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 55, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 91, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128
Offset: 1

Views

Author

Robert G. Wilson v, Aug 08 2001

Keywords

Comments

This is also the set of highest rolls that can be made with some number of platonic dice (dice which are platonic solids, considered to be the most "fair" dice). For instance, 22 is the highest roll with a die which is a dodecahedron, a cubic die, and a tetrahedral die. - Joshua R. Tint, Sep 08 2020
Contains every even number > 2. Odd terms are A063131. - David A. Corneth, Sep 09 2020

Examples

			55 is in the sequence as 55 = 110111_2 and the largest proper divisor of 55 is 11 and 11 = 1011_2 which is contained in 110111_2. - _David A. Corneth_, Sep 08 2020

Crossrefs

Cf. A062238, A063131.

Programs

  • Mathematica
    Do[ If[ !PrimeQ[ n ] && StringPosition[ ToString[ FromDigits[ IntegerDigits[ n, 2 ] ] ], ToString[ FromDigits[ IntegerDigits[ Divisors[ n ] [ [ -2 ] ], 2 ] ] ] ] != {}, Print[ n ] ], {n, 2, 150} ]
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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