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 A123080 #6 Nov 21 2013 12:49:00 %S A123080 3,7,11,19,31,43,59,71,103,107,139,151,179,191,199,227,239,271,283, %T A123080 311,347,419,431,463,523,571,599,619,643,659,811,823,827,859,883,1019, %U A123080 1031,1051,1063,1091,1151,1231,1279,1291,1303,1319,1427,1451,1483,1487,1607 %N A123080 Twin primes of form 4k+3. %p A123080 i:=1:for k from 1 to 3000 do if isprime(k) and isprime(k+2) then b:=k:c:=k+2: if b mod 4 = 3 then a[i]:=b:i:=i+1 fi: if c mod 4 = 3 then a[i]:=c:i:=i+1 fi:fi od: seq(a[n],n=1..i-1); %t A123080 Select[Flatten[Select[Partition[Prime[Range[260]],2,1],Last[#]-First[#] == 2&]], IntegerQ[(#-3)/4]&] (* _Harvey P. Dale_, Apr 20 2011 *) %Y A123080 Cf. A122564, A122565, A001097. %K A123080 nonn %O A123080 1,1 %A A123080 _Miklos Kristof_, Sep 27 2006