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 A068080 #20 Sep 08 2022 08:45:05 %S A068080 1,2,3,7,15,19,31,33,35,37,51,65,69,77,79,85,91,95,97,133,139,141,143, %T A068080 145,157,159,161,177,187,199,209,211,213,215,217,229,235,247,255,267, %U A068080 271,299,303,307,319,331,335,337,339,341,345,365,367,371,379,391,393 %N A068080 Integers n such that n + phi(n) is a prime. %C A068080 The subsequence of prime terms is given by A005382. - _Michel Marcus_, Aug 22 2015 %H A068080 Amiram Eldar, <a href="/A068080/b068080.txt">Table of n, a(n) for n = 1..10000</a> %t A068080 Select[Range[400], PrimeQ[# + EulerPhi[#]] &] (* _Carl Najafi_, Aug 22 2011 *) %o A068080 (PARI) isok(n) = isprime(n+eulerphi(n)); \\ _Michel Marcus_, Aug 22 2015 %o A068080 (Magma) [n: n in [1..400] |IsPrime(n+EulerPhi(n))]; // _Vincenzo Librandi_, Dec 19 2015 %Y A068080 Cf. A050530. %K A068080 easy,nonn %O A068080 1,2 %A A068080 _Amarnath Murthy_, Feb 17 2002 %E A068080 Edited and extended by _Robert G. Wilson v_, Feb 18 2002