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A123181 Numbers such that (-1)Sigma(m)*UnitarySigma(m)= k*UnitaryPhi(m)*m for some integer k. 1
1, 6, 312, 495, 990, 20520, 23664, 64416, 13063050 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

R. J. Mathar did an exhaustive search up to 74000000. Kohmoto found one more term, 2^8*3*11*43*257*509 with k=3, but between 7.4*10^7 and this term, many terms may be missing.

LINKS

Table of n, a(n) for n=1..9.

MAPLE

isA123181 := proc(m)

A047994(m) ;

modp(A049060(m)*A034448(m), %*m) = 0 ;

end proc:

for m from 1 do

if isA123181(m) then

printf("%a, \n", m) ;

end if;

end do: # R. J. Mathar, Sep 04 2018

CROSSREFS

Cf. A123182, A049060, A034448, A047994.

Sequence in context: A280215 A015103 A282373 * A281932 A074656 A233108

Adjacent sequences: A123178 A123179 A123180 * A123182 A123183 A123184

KEYWORD

nonn,more

AUTHOR

Yasutoshi Kohmoto, Oct 03 2006

EXTENSIONS

1 preprended by R. J. Mathar, Sep 04 2018

STATUS

approved

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Last modified December 7 13:02 EST 2022. Contains 358656 sequences. (Running on oeis4.)