

A333408


Numbers k such that s(k) = s(k+1), where s(k) is the unitary analog of the alternating sumofdivisors function (A307037).


1



1, 11, 71, 155, 194, 204, 1119, 1420, 1628, 3705, 5186, 14363, 19788, 20467, 25180, 25545, 25843, 28251, 30804, 42811, 60204, 63180, 71791, 73260, 83600, 87219, 87308, 91539, 97432, 99208, 100456, 100471, 119315, 122616, 132308, 135340, 135864, 164691, 166624
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OFFSET

1,2


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..1000


EXAMPLE

1 is a term since s(1) = s(2) = 1;
11 is a term since s(11) = s(12) = 10;


MATHEMATICA

f[p_, e_] := p^e + (1)^e; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; seq = {}; s1 = 1; Do[s2 = s[n]; If[s1 == s2, AppendTo[seq, n  1]]; s1 = s2, {n, 2, 10^5}]; seq


CROSSREFS

The unitary version of A206368.
Cf. A206369, A307037.
Sequence in context: A255205 A117047 A089720 * A174202 A139850 A233416
Adjacent sequences: A333405 A333406 A333407 * A333410 A333411 A333412


KEYWORD

nonn


AUTHOR

Amiram Eldar, Mar 19 2020


STATUS

approved



