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Numbers n such that sigma(reverse(n)) = phi(n).
4

%I #11 Feb 11 2014 19:05:28

%S 1,120,260,450,861,1411,1541,1550,7372,7957,8393,9312,13811,14840,

%T 20440,26060,38323,41550,46990,49813,51412,61050,77695,78625,86691,

%U 94604,94632,138631,143520,166331,169360,176820,182750,208150,236220,236840,270650

%N Numbers n such that sigma(reverse(n)) = phi(n).

%H Donovan Johnson, <a href="/A070856/b070856.txt">Table of n, a(n) for n = 1..1000</a>

%e sigma(reverse(120)) = sigma(21) = 32 = phi(120), so 120 is a term of the sequence.

%t Select[ Range[ 10^6 ],EulerPhi[ # ]==DivisorSigma[ 1,FromDigits[ Reverse[ IntegerDigits[ # ] ] ] ]& ]

%Y Cf. A000203, A000010, A004086, A070835.

%K base,nonn

%O 1,2

%A _Joseph L. Pe_, May 16 2002

%E Extended by _Ray Chandler_, Feb 10 2009