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 A230852 #14 May 28 2015 16:46:35 %S A230852 0,0,0,0,0,59,0,0,205,229,167,353,1595,4459,6407,6215,14995,4559,4697, %T A230852 11399,365,10199,19327,39103,3185,13649,15787,2693,21455,24929,32209, %U A230852 30509,13421,5389,36947,12869,27277,38389,973,69199,58835,165629,52597,25463,17923,38629,90263,17153,48143,2171,1255 %N A230852 Smallest k<3*2^n such that 3*2^n+k is the smallest of four consecutive primes in arithmetic progression or 0 if no solution. %C A230852 Conjecture: if n>8 there is always a solution. %H A230852 Pierre CAMI, <a href="/A230852/b230852.txt">Table of n, a(n) for n = 1..110</a> %e A230852 3*2^6+59=251, and 251, 257, 263, 269 are four consecutive primes in arithmetic progression 6 so a(6)=59. %e A230852 3*2^9+205=1741, and 1741, 1747, 1753, 1759 are four consecutive primes in arithmetic progression 6 so a(9)=205. %o A230852 (PARI) cpap4(p)=my(q=nextprime(p+1),g=q-p);nextprime(q+1)-q==g&&nextprime(p+2*g+1)==p+3*g %o A230852 a(n)=forprime(p=3<<n,6<<n,if(cpap4(p),return(p-3<<n))) \\ _Charles R Greathouse IV_, Oct 31 2013 %Y A230852 Cf. A054800, A230699. %K A230852 nonn %O A230852 1,6 %A A230852 _Pierre CAMI_, Oct 31 2013