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%I #24 Feb 26 2018 09:16:26
%S 24,40,60,88,132,184,220,232,276,348,328,460,424,492,580,636,664,712,
%T 820,1012,904,996,1060,1068,1048,1276,1356,1384,1432,1660,1572,1804,
%U 1528,1780,1864,1912,2076,2332,2260,2148,2008,2292,2668,2248,2620,2344,2796,2868,3012,2872,3460,3652,3772,3372
%N phi(A157352(n)), n >= 1, where phi is Euler's totient function A000010, and A157352 gives the products of two distinct safe primes.
%C phi(p*q) = (p-1)(q-1) where p, q are distinct safe primes.
%C 2^(a(n)/2) == 1 (mod A157352(n)). For the reference see a comment on A269454. - _Wolfdieter Lang_, Mar 31 2016
%H Vincenzo Librandi, <a href="/A269452/b269452.txt">Table of n, a(n) for n = 1..1500</a>
%F a(n) = phi(A157352(n)), n >= 1.
%t EulerPhi /@ Select[Select[Range@ 4000, PrimeNu@ # == 2 &], Times @@ Map[If[PrimeQ[(# - 1)/2], #, 0] &, Map[First, FactorInteger@ #]] == # &] (* _Michael De Vlieger_, Feb 28 2016 *)
%Y Cf. A000010, A157352, A269454.
%K nonn
%O 1,1
%A _Marina Ibrishimova_, Feb 27 2016
%E More terms from _Michael De Vlieger_, Feb 28 2016
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