A122846 Sequence gives k numbers from A122839.

1, 9, 4, 36, 16, 9, 81, 4, 64, 35, 36, 49, 16, 25, 144, 15, 9, 16, 100, 81, 49, 4, 64, 35, 36, 196, 16, 15, 25, 49, 25, 144, 9, 60, 9, 100, 64, 100, 121, 15, 16, 81, 16, 4, 81, 9, 25, 16, 49, 4, 25, 16, 121, 25, 35, 256, 114, 36, 35, 81, 4, 49, 16, 16, 36, 4, 64

Offset

1,2

Comments

Almost all terms are squares.

Links

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

Formula

a(n) = f(A122839(n)), where f(m) = A000203(m)*A034448(m)/A047994(m)^2. - Amiram Eldar, Dec 11 2019

Mathematica

f[p_, e_] := (p^(e+1)-1)*(p^e+1)/(p-1)/(p^e-1)^2; ratio[1] = 1; ratio[n_] := Times @@ (f @@@ FactorInteger[n]); Select[ratio /@ Range[10^5], IntegerQ] (* Amiram Eldar, Dec 11 2019 *)

Crossrefs

Cf. A000203, A034448, A047994, A122839.

Sequence in context: A104728 A058093 A164032 * A248309 A317900 A298583

Adjacent sequences: A122843 A122844 A122845 * A122847 A122848 A122849

Keyword

nonn

Author

Yasutoshi Kohmoto, Oct 23 2006

Extensions

More terms from Amiram Eldar, Dec 11 2019

Status

approved