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.

A235490 Numbers such that none of their prime factors share common 1-bits in the same bit-position and when added (or "ored" or "xored") together, yield a term of A000225 (a binary "repunit").

Table of values

n a(n)
1 1
2 3
3 7
4 10
5 26
6 31
7 58
8 122
9 127
10 1018
11 2042
12 8186
13 8191
14 32762
15 131071
16 524287
17 2097146
18 8388602
19 33554426
20 1073741818
21 2147483647
22 2305843009213693951
23 618970019642690137449562111
24 39614081257132168796771975162
25 162259276829213363391578010288127
26 166153499473114484112975882535043066

List of values

[1, 3, 7, 10, 26, 31, 58, 122, 127, 1018, 2042, 8186, 8191, 32762, 131071, 524287, 2097146, 8388602, 33554426, 1073741818, 2147483647, 2305843009213693951, 618970019642690137449562111, 39614081257132168796771975162, 162259276829213363391578010288127, 166153499473114484112975882535043066]

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

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