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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A230301 Positive numbers not of the form m + wt(m-1), m >= 1.

Original entry on oeis.org

2, 5, 7, 14, 16, 19, 22, 24, 31, 33, 38, 40, 47, 49, 52, 55, 57, 64, 72, 79, 81, 84, 87, 89, 96, 98, 103, 105, 112, 114, 117, 120, 122, 129, 131, 134, 136, 143, 145, 148, 151, 153, 160, 162, 167, 169, 176, 178, 181, 184, 186, 193, 201, 208, 210, 213, 216, 218, 225, 227, 232, 234, 241, 243, 246, 249, 251, 271, 273, 276
Offset: 1

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Author

N. J. A. Sloane, Oct 23 2013

Keywords

Comments

wt(m) = A000120(m).
These are numbers k such that A228085(2^k) = A228085(k-1) = 0, or numbers k such that 2^k is a binary self number (A010061). - Amiram Eldar, Feb 23 2021

Links

Crossrefs

Cf. A000120, A010061, A228085, A230300, A232491.

Formula

a(n) = A010061(n) + 1.

A272652 a(n) is the smallest even number which has n inverse images under the map x -> x + (binary weight of x).

Original entry on oeis.org

0, 14, 134, 4102, 87112285931760246646623899502532662132742, 1852673427797059126777135760139006525652319754650249024631321344126610074239106
Offset: 1

Views

Author

Max Alekseyev and N. J. A. Sloane, May 13 2016

Keywords

Comments

If the word "even" is omitted the sequence is A230303.
The next term is a(7) = 2^4233 + 130.

Examples

			The smallest number with two inverses is 14: the inverses are 11 = 1011_2 which maps to 11+3 = 14, and 12 = 1100_2 which maps to 12+2 = 14.

Crossrefs

Cf. A230303, A000120, A092391, A228085.
Previous Showing 21-22 of 22 results.

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

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