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 A094486 #11 Apr 30 2014 01:37:05 %S A094486 2,2472973457,6115597639891380737 %N A094486 Primes of form 2^j + 223^j. %C A094486 Expression 2^j + q^j below q = prime <= prime[130] provided always prime at j=0; or for j=1 if q is a lesser-twin-prime; or more rarely 3 or 4 primes [four ones at q=3,5,17,37,59,137,179,223,461]; never found 5 or more relevant primes and the corresponding exponents proved to be powers of 2. Formal proofs of observations wanted. %C A094486 See comment by _Michael Somos_, Aug 27 2004 for proof that j must be zero or a power of 2. - _Robert Price_, Apr 30 2013 %C A094486 Since the number j must be zero or a power of 2, checked j being powers of two through 2^19. Thus a(5) > 10^2400000. Primes of this magnitude are rare (about 1 in 5.6 million), so chance of finding one is remote with today's computer algorithms and speeds. - _Robert Price_, Apr 30 2013 %e A094486 The relevant exponents are powers of 2: 0,4,8,128. a(4) = 2^128 + 223^128 = 382844.....1067137 (a prime with 301 decimal digits). %Y A094486 Cf. A082101, A094473-A094485. %K A094486 nonn,bref %O A094486 1,1 %A A094486 _Labos Elemer_, Jun 01 2004 %E A094486 Corrected by _T. D. Noe_, Nov 15 2006