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A238231 Numbers n such that if x=phi(n)*tau(n)-sigma(n)-n then n=phi(x)*tau(x)-sigma(x)-x. 0
376, 594, 846, 1178, 1222, 46498, 65198 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(8) > 2*10^9. - Giovanni Resta, Mar 26 2014

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

Fixed points: 376,...

phi(594) = 180, tau(594) = 16, sigma(594) = 1440 and 180*16 - 1440 - 594 = 846.

phi(846) = 276, tau(846) = 12, sigma(846) = 1872 and 276*12 - 1872 - 846 = 594.

MAPLE

with(numtheory); P:=proc(q)local a, n;

for n from 1 to q do a:=phi(n)*tau(n)-sigma(n)-n;

if a>0 and phi(a)*tau(a)-sigma(a)-a=n then print(n);

fi; od; end: P(10^6);

CROSSREFS

Cf. A000005, A000010, A000203, A238225-A238230.

Sequence in context: A251652 A251645 A259769 * A008853 A188007 A251644

Adjacent sequences: A238228 A238229 A238230 * A238232 A238233 A238234

KEYWORD

nonn,more

AUTHOR

Paolo P. Lava, Feb 20 2014

STATUS

approved

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Last modified December 2 13:38 EST 2022. Contains 358510 sequences. (Running on oeis4.)