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A067341 Number of prime factors divided by the number of distinct prime factors is an integer and n is neither squarefree, nor power of prime. 1
24, 36, 40, 54, 56, 88, 96, 100, 104, 135, 136, 144, 152, 160, 184, 189, 196, 216, 224, 225, 232, 240, 248, 250, 296, 297, 324, 328, 336, 344, 351, 352, 360, 375, 376, 384, 400, 416, 424, 441, 459, 472, 484, 486, 488, 504, 513, 528, 536, 540, 544, 560, 568 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

A001222(n)/A001221(n) is integer, A001222(n)>A001221(n)>1.

MATHEMATICA

ff[x_] := Flatten[FactorInteger[x]] f1[x_] := Length[FactorInteger[x]] f2[x_] := Apply[Plus, Table[Part[ff[x], 2*w], {w, 1, f1[x]}]] Do[s=f2[n]/f1[n]; If[IntegerQ[s]&&Greater[s, 1]&&Greater[f1[n], 1], Print[n]], {n, 2, 10000}]

PROG

(PARI) is(n)=my(f=factor(n)[, 2]); #f>1 && vecsum(f)%#f==0 && vecmax(f)>1 \\ Charles R Greathouse IV, Oct 15 2015

CROSSREFS

Cf. A001221, A001222, A067340.

Sequence in context: A224907 A292352 A307342 * A307682 A290016 A195008

Adjacent sequences:  A067338 A067339 A067340 * A067342 A067343 A067344

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 16 2002

STATUS

approved

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Last modified January 27 15:14 EST 2020. Contains 331295 sequences. (Running on oeis4.)