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 A225148 #16 May 03 2013 13:56:51 %S A225148 127,1093,2801,19531,22621,30941,55987,88741,131071,245411,292561, %T A225148 346201,524287,637421,732541,797161,837931,2625641,3500201,3835261, %U A225148 5229043,6377551,8108731,12207031,15018571,16007041,21700501,25646167,28792661,30397351,35615581 %N A225148 Primes of the form (k^p-1)/(k-1) not having representation in the form (m^q+1)/(m+1), where k,m > 1 and p,q > 2. %C A225148 The exponent p must be a prime p > 3. If p=3 then (k^p-1)/(k-1) = (m^q+1)/(m+1) for m=k+1 and q=3. %C A225148 Are almost all primes of the form (k^p-1)/(k-1), where k > 1 and p > 3, in the sequence? Except 31 and 8191. See: %C A225148 31 = (2^5-1)/(2-1) = (5^3-1)/(5-1) = (6^3+1)/(6+1), %C A225148 8191 = (2^13-1)/(2-1) = (90^3-1)/(90-1) = (91^3+1)/(91+1). %F A225148 Numbers in A085104 but not in A059055. %Y A225148 Cf. A085104, A059055. %K A225148 nonn %O A225148 1,1 %A A225148 _Thomas Ordowski_, Apr 30 2013 %E A225148 Extended by _T. D. Noe_, Apr 30 2013