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.

A226647 Numbers k such that Sum_{i=1..k} sigma(i) is divisible by Sum_{i=1..k} d(i), where sigma(i) = sum of divisors of i (A000203), and d(i) = number of divisors of i (A000005).

Table of values

n a(n)
1 1
2 9
3 25
4 37
5 63
6 71876888199

List of values

[1, 9, 25, 37, 63, 71876888199]

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

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