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A125314 Smallest number k>1 such that Sum_{i=1..k} i^n divides Product_{i=1..k} i^n. 7
3, 7, 3, 31, 13, 1556, 733, 89037, 1441, 668073 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Sum[ i^n, {i,1,k} ] = Zeta[ -n ] - Zeta[ -n, k+1 ]. Product[ i^n, {i,1,k} ] = (k!)^n.

a(11) > 1091730. - Robert G. Wilson v, Jan 25 2007

LINKS

Table of n, a(n) for n=1..10.

MATHEMATICA

f[n_] := Block[{k = 2, p = s = 1}, While[p = p*k; s = s + k^n; PowerMod[p, n, s] != 0, k++ ]; k]; (* Robert G. Wilson v *)

CROSSREFS

Sequence in context: A019158 A086153 A049479 * A213244 A050393 A110778

Adjacent sequences:  A125311 A125312 A125313 * A125315 A125316 A125317

KEYWORD

hard,more,nonn

AUTHOR

Alexander Adamchuk, Jan 18 2007

EXTENSIONS

a(8)-a(10) from Robert G. Wilson v, Jan 25 2007

STATUS

approved

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Last modified April 25 16:08 EDT 2019. Contains 322461 sequences. (Running on oeis4.)