

A123181


Numbers such that (1)Sigma(m)*UnitarySigma(m)= k*UnitaryPhi(m)*m for some integer k.


1




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



