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 A091968 #25 Jul 01 2016 22:50:58 %S A091968 3,19,67,83,131,163,179,211,227,307,419,467,499,547,563,643,659,691, %T A091968 739,787,883,947,1091,1123,1171,1187,1283,1427,1459,1523,1571,1619, %U A091968 1667,1699,1747,1811,1907,1987,2003,2083,2099,2131,2179,2243,2339,2371,2467 %N A091968 Primes congruent to 3 (mod 16). %C A091968 For any n, the equations x^4 - y^4 = a(n)*z^2 and x^4 - a(n)^2*y^4 = z^2 are not solvable in natural numbers. - _Arkadiusz Wesolowski_, Aug 15 2013 %D A091968 L. J. Mordell, Diophantine Equations, Ac. Press, p. 23. %D A091968 Trygve Nagell, Introduction to Number Theory, Chelsea Publishing Company, NY, 1964, p. 230. %H A091968 T. D. Noe, <a href="/A091968/b091968.txt">Table of n, a(n) for n = 1..1000</a> %t A091968 Select[Prime@Range[400], Mod[ #, 16] == 3 &] (* _Ray Chandler_, Dec 06 2006 *) %o A091968 (PARI) is(n)=isprime(n) && n%16==3 \\ _Charles R Greathouse IV_, Jul 01 2016 %Y A091968 Cf. A092022, A093012. %K A091968 nonn,easy %O A091968 1,1 %A A091968 _Giovanni Teofilatto_, Mar 14 2004 %E A091968 More terms from _Ray Chandler_, Mar 15 2004