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A349007
a(1) = 1; for n > 1, a(n) is the largest number m such that sigma(m) = tau(m)^n or 0 if no such m exists.
5
1, 3, 7, 2667, 27559, 677207307, 225735769, 698915267211, 29587412978599, 811637999283747, 16907189874529, 12200855315219510767697163, 254155396405925065290841, 878412242330556407427, 1074593611687774330088252281, 16138807601873739769, 37471768236581557067194399
OFFSET
1,2
COMMENTS
See A051281 for numbers m such that sigma(m) = tau(m)^k where k = integer.
a(n) = 0 for n = 76, 81, ...
EXAMPLE
a(4) = 2667 because 2667 is the largest number m such that sigma(m) = tau(m)^4; sigma(2667) = 4096 = tau(2667)^4 = 8^4.
PROG
(PARI) See Links section.
CROSSREFS
Subsequence of A051281.
Cf. A000005 (tau), A000203 (sigma), A334455, A349006.
Sequence in context: A062625 A175986 A296351 * A101006 A372769 A306632
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Nov 05 2021
STATUS
approved