A127046 - OEIS

A127046

Primes p such that denominator of Sum_{k=1..p-1} 1/k^3 is a cube.

2, 3, 5, 11, 13, 17, 29, 31, 37, 41, 83, 89, 97, 137, 139, 293, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103

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OFFSET

1,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

MATHEMATICA

d[n_] := Module[{}, su = 0; a = {}; For[i = 1, i <= n, i++, su = su + 1/ i^3; If[PrimeQ[i + 1], If[IntegerQ[(Denominator[su])^(1/3)], AppendTo[a, i + 1]]]]; a]; d[2000]

Select[Prime[Range[200]], IntegerQ[Surd[Denominator[Sum[1/k^3, {k, #-1}]], 3]]&] (* Harvey P. Dale, Mar 13 2013 *)

CROSSREFS

Cf. A061002, A034602, A127029, A127042.

Sequence in context: A253110 A140549 A275697 * A127051 A127045 A328514

Adjacent sequences: A127043 A127044 A127045 * A127047 A127048 A127049

KEYWORD

nonn

AUTHOR

Artur Jasinski, Jan 03 2007

STATUS

approved