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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.

A258722 a(n) is the smallest k (powers of 10 excluded) such that sod(k), sod(k^2),..., sod(k^n) is an arithmetic progression, where sod(m) = A007953(m) is the sum of the digits of m.

Table of values

n a(n)
3 4
4 4
5 16
6 16
7 16
8 7972
9 7972
10 134242
11 59716233
12 1844284813
13 77298251764

List of values

[4, 4, 16, 16, 16, 7972, 7972, 134242, 59716233, 1844284813, 77298251764]

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

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