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 A193598 #11 May 13 2013 01:54:20 %S A193598 2,18,30,42,52,54,66,68,70,78,90,98,100,102,110,112,114,126,128,130, %T A193598 138,150,152,162,172,174,182,190,198,210,222,230,232,234,236,238,240, %U A193598 242,244,250,258,268,270,282,284,286,290,292,294,306,308 %N A193598 Even numbers k such that r(k) < r(k/2), where r(n) is the distance from n to the nearest prime. %H A193598 Charles R Greathouse IV, <a href="/A193598/b193598.txt">Table of n, a(n) for n = 1..10000</a> %e A193598 18 is in the sequence, since r(18) = 1 < 2 = r(9); 22 is not in the sequence, since r(22) = 1 >= 0 = r(11). %o A193598 (PARI) r(n)=min(nextprime(n)-n,n-precprime(n)) %o A193598 forstep(k=2,1e3,2,if(r(k)<r(k/2),print1(k", "))) \\ _Charles R Greathouse IV_, Jul 31 2011 %Y A193598 r(n) is A051699. %K A193598 nonn %O A193598 1,1 %A A193598 _Vladimir Shevelev_, Jul 31 2011