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 A054820 #12 Oct 13 2013 17:36:50 %S A054820 19,43,83,109,229,283,313,349,353,383,401,443,463,503,571,643,677,683, %T A054820 829,859,883,911,1033,1063,1093,1193,1231,1279,1303,1321,1373,1429, %U A054820 1433,1453,1489,1493,1553,1609,1621,1627,1699,1879,1999,2029,2089,2161 %N A054820 Second term of weak prime quartet: p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1). %C A054820 Lesser of a pair p(m), p(m+1) of consecutive weak primes A051635. See A229832 for more comments, references and links. - _Jonathan Sondow_, Oct 13 2013 %C A054820 a(1) = A229832(2). - _Jonathan Sondow_, Oct 13 2013 %Y A054820 Cf. A051635, A054800-A054840, A229832. %K A054820 nonn %O A054820 1,1 %A A054820 _Henry Bottomley_, Apr 10 2000