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 A152866 #5 Mar 30 2012 17:27:56
%S A152866 5,43,139,227,277,773,947,991,1237,1481,1549,1601,1871,1993,2339,3119,
%T A152866 3169,3217,3259,3371,3709,3853,4013,4219,4483,4951,5051,5107,5147,
%U A152866 5419,5527,6637,6977,7477,7699,8539,10139,10267,11783,11981,12163,12263
%N A152866 Beginnings of maximal chains of primes with three members (two links).
%C A152866 For definitions see A152658, of which this is a subsequence.
%H A152866 Klaus Brockhaus, <a href="/A152866/b152866.txt">Table of n, a(n) for n=1..1000</a>
%e A152866 First maximal chain of primes with three members (two links) is 5, 7, 11; the linking primes are 43, 83.
%o A152866 (PARI) {n=1; while(n<1470, c=0; a=prime(n); while(isprime(n*prime(n)+(n+1)*prime(n+1)), c++; n++); if(c==2, print1(a, ",")); n++)}
%Y A152866 Cf. A152658 (beginnings of maximal chains of primes), A152735 (count of links in n-th maximal chain of primes), A152962 (beginning of the first maximal chain of primes with n links), A152865, A152867, A152868, A152869, A152963, A152964.
%K A152866 nonn
%O A152866 1,1
%A A152866 _Klaus Brockhaus_, Dec 17 2008