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.

A117581 For each successive prime p, the largest integer n such that both n and n-1 factor into primes less than or equal to p.

Table of values

n a(n)
1 2
2 9
3 81
4 4375
5 9801
6 123201
7 336141
8 11859211
9 11859211
10 177182721
11 1611308700
12 3463200000
13 63927525376
14 421138799640
15 1109496723126
16 1453579866025
17 20628591204481
18 31887350832897
19 31887350832897
20 119089041053697
21 2286831727304145
22 9591468737351909376
23 9591468737351909376
24 9591468737351909376
25 9591468737351909376
26 9591468737351909376
27 19316158377073923834001

List of values

[2, 9, 81, 4375, 9801, 123201, 336141, 11859211, 11859211, 177182721, 1611308700, 3463200000, 63927525376, 421138799640, 1109496723126, 1453579866025, 20628591204481, 31887350832897, 31887350832897, 119089041053697, 2286831727304145, 9591468737351909376, 9591468737351909376, 9591468737351909376, 9591468737351909376, 9591468737351909376, 19316158377073923834001]

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

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