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 A130076 #23 Feb 25 2023 03:05:51
%S A130076 2,3,5,19
%N A130076 Primes p such that p^2 divides 5^p - 3^p - 2^p.
%C A130076 For a prime p, p divides A130072(p) = 5^p - 3^p - 2^p. Quotients A130072(p)/p are listed in A130075.
%C A130076 If p^2 divides A130072(p), then p^(k+1) divides A130072(p^k) for every k>0. For p = 19, even 19^(k+2) divides A130072(p^k).
%C A130076 Numbers n such that n divides A130072(n) are listed in A130073. Nonprimes n such that n divides A130072(n) are listed in A130074, which apparently include all powers p^k of primes p = {2,3,5,19} for k>1 and all powers of numbers of the form 2^k*3^m, 3^k*5^m, 5^k*19^m.
%C A130076 No other terms below 10^11. - _Max Alekseyev_, Dec 06 2010
%e A130076 p^2 divides A130072(p) = 5^p - 3^p - 2^p for prime p = {2,3,5,19}, quotients A130072(p)/p^2 are {3,10,114,52831921170}.
%t A130076 fQ[p_]:=Mod[PowerMod[5,p,p^2]-PowerMod[3,p,p^2]-PowerMod[2,p,p^2],p^2]==0 (* _Robert G. Wilson v_, Mar 14 2011 *)
%o A130076 (PARI) forprime(p=2,1e9,if(Mod(5,p^2)^p==Mod(3,p^2)^p+Mod(2,p^2)^p,print1(p", "))) \\ _Charles R Greathouse IV_, Mar 14 2011
%Y A130076 Cf. A130072, A130073, A130074, A130075.
%K A130076 bref,hard,more,nonn
%O A130076 1,1
%A A130076 _Alexander Adamchuk_, May 06 2007
%E A130076 Edited by _Max Alekseyev_, Dec 05 2010