[seqfan] Re: a(n) = (sigma(a(n)) - phi(a(n)))/k for some k

[M. F. Hasler]

See https://oeis.org/A055681

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Maximilian

On Mon, Jul 8, 2019, 14:48 юрий герасимов <2stepan at rambler.ru> wrote:

> Hello, SeqFans, a(n): 2 (k = 1), 12 (2), 42 (2), 1242 (2), 75920 (3),
> 1447488
> (3), 3506976 (3), 61337440 (2)
> This sequence is finite or infinite ? Thank you. Juri-Stepan Gerasimov
>