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 A259238 #10 Aug 28 2015 18:56:42 %S A259238 -3,-5,-8,3,-7,-9,9,-7,7,-11,3,-15,1,-17,-13,-15,-1,-13,2,-20,5,-19, %T A259238 -21,5,-23,-27,-15,-3,-28,-25,13,-4,-1,-35,-29,4,-39,-35,1,-41,-25, %U A259238 -39,7,3,-39,13,-31,-21,7,-40,-35,-3,9,23,-31,1,-33,-29,21,-31,-44 %N A259238 The bases corresponding to A257751. %H A259238 Tim Johannes Ohrtmann, <a href="/A259238/b259238.txt">Table of n, a(n) for n = 1..14679</a> %e A259238 a(1) = -3 because this is the integer except 0 such that for every prime factor p of A257751(1) applies that p+b divides n+b: 35=5*7 and 2, 4 both divide 32. %o A259238 (PARI) for(n=2, 1000000, if(!isprime(n), if(issquarefree(n), f=factor(n); k=0; for(b=-(f[1, 1]-1), n, c=0; for(i=1, #f[, 1], if((n+b)%(f[i, 1]+b)>0, c++)); if(c==0, if(!b==0, k++; a=b))); if(k==1, print1(a, ", "))))) %K A259238 sign %O A259238 1,1 %A A259238 _Tim Johannes Ohrtmann_, Jun 22 2015