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 A080062 #8 May 17 2016 04:02:36
%S A080062 4,8,9,16,25,27,32,45,49,64,81,121,125,128,169,225,243,256,289,325,
%T A080062 343,361,405,512,529,561,625,637,729,841,891,961,1024,1105,1125,1225,
%U A080062 1331,1369,1377,1681,1729,1849,2025,2048,2187,2197,2209,2401,2465,2809,2821
%N A080062 Composite numbers n such that for all primes p dividing n, p-1 divides n-1.
%C A080062 The subsequence of squarefree terms gives the Carmichael numbers (A002997); cf. Korselt's criterion. - _Joerg Arndt_, May 17 2016
%H A080062 Donovan Johnson, <a href="/A080062/b080062.txt">Table of n, a(n) for n = 1..10000</a>
%H A080062 Wikipedia, <a href="https://en.wikipedia.org/wiki/Carmichael_number#Korselt.27s_criterion">Korselt's criterion</a>
%t A080062 Select[ Range[2, 10^4], !PrimeQ[ # ] && Union[ Mod[ # - 1, Transpose[ FactorInteger[ # ]][[1]] - 1]] == {0} &]
%o A080062 (PARI) is080062(n)=if(isprime(n),return(0)); my(f=factor(n)[, 1]); for(j=1, #f, if((n-1)%(f[j]-1), return(0))); 1; \\ _Joerg Arndt_, May 17 2016
%Y A080062 Cf. A056729, A079543.
%Y A080062 Cf. A002997 (Carmichael numbers).
%K A080062 nonn
%O A080062 1,1
%A A080062 _Robert G. Wilson v_, Jan 23 2003