

A098215


Numbers n such that reverse(sigma(n)) = n  phi(n) = cototient(n).


0



136, 261, 295, 493, 1218, 1576, 15976, 159976, 715381, 717181, 746341, 987109, 1585576, 5989003, 13390567, 14400136, 19326607, 78753211, 144144136, 145454536, 158401576, 275675661, 713791681, 737098261, 1440000136, 1441584136, 1454414536, 1455998536
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..28.


EXAMPLE

n=5989003: sigma(n) = 5994000 and n  phi(n) = 4995


MATHEMATICA

Do[ If[ FromDigits[ Reverse[ IntegerDigits[ DivisorSigma[1, n]]]] == n  EulerPhi[n], Print[n]], {n, 10^8}] (* Robert G. Wilson v, Oct 23 2004 *)


CROSSREFS

Cf. A069225, A000203, A000010.
Sequence in context: A264958 A262615 A101335 * A247439 A183635 A116223
Adjacent sequences: A098212 A098213 A098214 * A098216 A098217 A098218


KEYWORD

base,nonn


AUTHOR

Labos Elemer, Oct 22 2004


EXTENSIONS

More terms from Robert G. Wilson v, Oct 27 2004
a(19)a(28) from Donovan Johnson, Jan 14 2011


STATUS

approved



