A348586 - OEIS

A348586

Numbers k such that abs(A328258(k)) = abs(A328258(k+1)).

1, 11, 40, 179, 695, 928, 991, 1079, 2772, 2799, 2839, 6687, 7632, 7739, 7960, 8568, 9347, 10703, 11008, 11472, 12847, 12935, 13580, 14064, 16000, 16260, 17135, 20944, 26432, 27999, 35399, 37236, 42251, 42756, 44199, 55308, 56419, 68976, 70127, 74671, 77748, 83099

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OFFSET

1,2

COMMENTS

Equivalently, numbers k such that A328258(k) = -A328258(k+1).

LINKS

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

EXAMPLE

1 is a term since abs(A328258(1)) = abs(A328258(2)) = 1.

11 is a term since abs(A328258(11)) = abs(A328258(12)) = 12.

MATHEMATICA

f[p_, e_] := 1 - (-1)^p*(p^e); s[1] = 1; s[n_] := Abs[Times @@ (f @@@ FactorInteger[n])]; Select[Range[10^5], s[#] == s[# + 1] &]