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A175795 Numbers n such that the digits of sigma(n) are exactly the same (albeit in different order) as the digits of phi(n), in base 10.

%I A175795 #16 Dec 13 2015 12:41:56
%S A175795 1,65,207,1769,2066,2771,3197,4330,4587,4769,4946,5067,6443,6623,6989,
%T A175795 7133,8201,9263,11951,12331,13243,16403,17429,17441,21416,22083,23161,
%U A175795 24746,27058,27945,28049,28185,28451,29111,30551,31439,32554,32566,32849,33715
%N A175795 Numbers n such that the digits of sigma(n) are exactly the same (albeit in different order) as the digits of phi(n), in base 10.
%H A175795 Donovan Johnson, <a href="/A175795/b175795.txt">Table of n, a(n) for n = 1..1000</a>
%e A175795 2771 is in the sequence because sigma(2771) = 2952, phi(2771) = 2592
%t A175795 okQ[n_] := Module[{idn = IntegerDigits[DivisorSigma[1,n]]}, Sort[idn] == Sort[IntegerDigits[EulerPhi[n]]]]; Select[Range[40000], okQ]
%o A175795 (Python)
%o A175795 from sympy import totient, divisor_sigma
%o A175795 A175795_list = [n for n in range(1,10**4) if sorted(str(divisor_sigma(n))) == sorted(str(totient(n)))] # _Chai Wah Wu_, Dec 13 2015
%o A175795 (PARI) isok(n) = (de = digits(eulerphi(n))) && (ds = digits(sigma(n))) && (vecsort(de) == vecsort(ds)); \\ _Michel Marcus_, Dec 13 2015
%Y A175795 Cf. A000010 (Euler totient function), A000203 (sigma function), A115920, A115921, A114065.
%K A175795 nonn,base
%O A175795 1,2
%A A175795 _Michel Lagneau_, Sep 06 2010