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 A262252 #9 Sep 21 2015 20:38:24 %S A262252 598,1886,11590,21098,24734,32578,91078,95170,107606,134930,143318, %T A262252 179998,253598,258482,259010,287274,361730,374402,568514,706142, %U A262252 751394,831290,920782,1074026,1105646,1327562,1514602,1548318,1579394,1742830,1794854,1808678,1952222 %N A262252 Even Quasi-Carmichael numbers. %H A262252 Tim Johannes Ohrtmann, <a href="/A262252/b262252.txt">Table of n, a(n) for n = 1..84</a> %e A262252 598 is even, composite and squarefree and at least one nonzero integer b exists such that for every prime factor p of n, p+b divides n+b (2): 598 = 2*13*23 and 4, 15, 25 all divide 600. %o A262252 (PARI) n=0; until(n==1000000, n+=2; if(!isprime(n), if(issquarefree(n), f=factor(n); k=0; b=0; until(b==n, b+=2; c=0; for(i=1, #f[, 1], if((n+b)%(f[i, 1]+b)>0, c++)); if(c==0, k++)); if(k>0, print1(n, ", "))))) %Y A262252 Cf. A029562, A029564, A029566, A029568, A029570, A257750. %K A262252 nonn %O A262252 1,1 %A A262252 _Tim Johannes Ohrtmann_, Sep 16 2015