A261341 - OEIS

A261341

Numbers n such that round(n^(1/k)) divides n for all integers k>=1.

1, 2, 4, 6, 12, 30, 36, 42, 72, 240, 420, 600, 900, 1560, 1764, 3600, 6084, 8100, 46440, 1742400, 4062240, 35814240

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OFFSET

1,2

COMMENTS

There are no other terms below 10^16.

Is this a finite sequence?

LINKS

MATHEMATICA

isA[n_] :=

Block[{t},

For[k = 2, (t = Floor[1/2 + n^(1/k)]) >= 2, k++,

If[Mod[n, t] != 0, Return[False]]]; Return[True]]

Select[Range[1, 100000], isA[#] &] (* Julien Kluge, Apr 04 2016 *)

PROG

(PARI) { isA261341(n) = my(k, t); k=2; until(t<=2, t=round(sqrtn(n, k)); if(n%t, return(0)); k++); 1; }

CROSSREFS

Subsequence of A006446 and A261342.

KEYWORD

nonn,more

AUTHOR

STATUS

approved