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 A141427 #12 Dec 29 2023 10:33:55 %S A141427 1,4,10,16,22,28,30,40,46,52,58,60,70,72,82,88,100,106,112,130,136, %T A141427 138,148,150,156,166,172,178,180,190,196,198,210,226,232,238,240,250, %U A141427 256,262,268,270,280,282,292,310,316,330,336,346,352,358,366,372,382,388 %N A141427 a(n) = phi(A067775(n)). %C A141427 Count of numbers smaller than and coprime to p for primes p such that p + 4 is composite. %C A141427 Subsequence of A006093. %o A141427 (PARI) {forprime(p=2, 400, if(!isprime(p+4), print1(eulerphi(p), ",")))} \\ _Klaus Brockhaus_, Aug 31 2008 %Y A141427 Cf. A067775, A000010 (Euler totient function), A006093 (primes minus 1), A141426, A141515. %K A141427 nonn %O A141427 1,2 %A A141427 _Giovanni Teofilatto_, Aug 06 2008 %E A141427 More terms from _Robert G. Wilson v_, Aug 18 2008 %E A141427 Edited by _N. J. A. Sloane_ and _Klaus Brockhaus_, Aug 31 2008