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 A225560 #6 Jun 02 2025 08:34:26 %S A225560 66747,18248,53097,2037018,142531,1691820,1322535,1659002,266251, %T A225560 6185640,95075,2518780,657645,325528,71971,2533260,21494113,682318, %U A225560 3114879,6523742,9196027,3588090,12492473,816078,14837001,12060370,2933065,12212058,3122953 %N A225560 Least numbers k for each base b >= 2 such that N = b^(2^n) + k is prime for 7 consecutive values from n = 0 to n = 6. %C A225560 Generalized Fermat numbers of the form b^(2^n) + k %o A225560 (PARI) for(b=2,30,if(b%2==0,a=1,a=0);forstep(k=a,10^8,2,i=0;for(n=0,6,m=b^2^n+k;if(isprime(m),i++;if(i>6,print1(k,", ");next(3)))))) %Y A225560 Cf. A070694, A225321, A225492 %K A225560 nonn %O A225560 2,1 %A A225560 _Robin Garcia_, May 10 2013