A123042 - OEIS

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A123042

Sequence gives k numbers from A123041.

1, 3, 2, 6, 4, 3, 9, 2, 8, 6, 7, 4, 5, 12, 3, 4, 10, 9, 7, 2, 8, 1, 6, 14, 4, 5, 7, 5, 3, 2, 12, 5, 3, 3, 2, 10, 8, 10, 11, 5, 4, 9, 4, 2, 9, 3, 5, 2, 4, 7, 2, 3, 5, 4, 11, 4, 5, 16, 6, 9, 2, 7, 4, 4, 6, 2, 8, 3, 2, 15, 2, 8, 4, 10, 4, 8, 15, 14, 4, 2, 1, 1, 2

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OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..4309

FORMULA

a(n) = A034448(A123041(n))^2/(A000203(A123041(n))*A047994(A123041(n))). - Amiram Eldar, Sep 12 2022

MATHEMATICA

f[p_, e_] := (p - 1)*(p^e + 1)^2/((p^e - 1)*(p^(e + 1) - 1)); s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[s /@ Range[10^5], IntegerQ] (* Amiram Eldar, Sep 12 2022 *)

CROSSREFS

Cf. A000203, A034448, A047994, A123041.

Sequence in context: A057050 A182546 A360265 * A121647 A339333 A339334

Adjacent sequences: A123039 A123040 A123041 * A123043 A123044 A123045

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto, Sep 24 2006

EXTENSIONS

More terms from Amiram Eldar, Sep 12 2022

STATUS

approved