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 A180923 #10 Dec 15 2017 17:37:11 %S A180923 2,16,18,20,26,28,30,38,40,42,46,56,60,62,68,72,82,86,88,96,110,112, %T A180923 118,130,132,138,140,150,156,158,160,166,178,192,196,210,216,220,226, %U A180923 228,240,242,248,250,266,276,278,280,290,292,300,306,320,326,342,348,350 %N A180923 Numbers n such that 111*n + 1 is prime. %t A180923 Select[Range[400], PrimeQ[111# + 1] &] (* _Harvey P. Dale_, Jan 04 2011 *) %o A180923 (PARI) is(n)=isprime(111*n+1) \\ _Charles R Greathouse IV_, Jun 13 2017 %K A180923 easy,nonn %O A180923 1,1 %A A180923 _Jason Earls_, Sep 25 2010