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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.

A019280 Let sigma_m(n) be result of applying the sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m(n) = k*n; sequence gives log_2 of the (2,2)-perfect numbers.

Table of values

n a(n)
1 1
2 2
3 4
4 6
5 12
6 16
7 18
8 30
9 60

List of values

[1, 2, 4, 6, 12, 16, 18, 30, 60]

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