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A064522 For an integer n with prime factorization p1*p2*p3* ... *pn let n* = (p1-1)*(p2-1)*(p3-1)* ... *(pn-1) (A003958); sequence gives n such that n is divisible by n*. 3
1, 2, 4, 6, 8, 12, 16, 20, 24, 32, 36, 40, 48, 64, 72, 80, 84, 96, 120, 128, 144, 160, 168, 192, 216, 240, 256, 272, 288, 312, 320, 336, 384, 400, 432, 440, 480, 504, 512, 544, 576, 624, 640, 672, 720, 768, 800, 864, 880, 960, 1008, 1024, 1088, 1152, 1248, 1280 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MAPLE

with(numtheory); ListA064522:=proc(q) local a, b, i, n;

for n from 1 to q do a:=ifactors(n)[2]; b:=mul((a[i][1]-1)^a[i][2], i=1..nops(a)); if type(n/b, integer) then print(n); fi; od; end: ListA064522(10^6); # Paolo P. Lava, Jul 02 2013

PROG

(PARI) nsm(n)= { local(f, p=1); f=factor(n); for(i=1, matsize(f)[1], p*=(f[i, 1] - 1)^f[i, 2]); return(p) } { n=0; for (m=1, 10^9, if (m%nsm(m) == 0, write("b064522.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 17 2009

CROSSREFS

Cf. A064476, A003958.

Sequence in context: A082662 A246663 A182568 * A036912 A306371 A097921

Adjacent sequences:  A064519 A064520 A064521 * A064523 A064524 A064525

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Oct 07 2001

STATUS

approved

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Last modified August 21 18:26 EDT 2019. Contains 326168 sequences. (Running on oeis4.)