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

KEYWORD

nonn

AUTHOR

Amiram Eldar, Mar 19 2020

STATUS

approved