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