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 A265731 #15 Jan 09 2016 00:26:42 %S A265731 8,9,16,25,32,36,64,81,100,125,128,144,169,196,225,243,256,289,324, %T A265731 343,400,441,512,576,625,676,784,841,900,1000,1024,1089,1156,1225, %U A265731 1296,1369,1521,1600,1681,1728,1764,1849,2025,2048,2197,2304,2500,2601,2704,2744,2809,2916,3025,3125 %N A265731 Powers C^z = A^x + B^y with all positive integers and x,y,z > 1, without multiplicity. %C A265731 This type of equation is used in the Fermat-Catalan conjecture, the ABC conjecture, etc., of course, with additional restrictions and conditions. %H A265731 Anatoly E. Voevudko, <a href="/A265731/b265731.txt">Table of n, a(n) for n = 1..7253</a> %H A265731 Anatoly E. Voevudko, <a href="/A265731/a265731.txt">Description of all powers in b265731</a> %H A265731 Anatoly E. Voevudko, <a href="/A245713/a245713.txt">Description of all powers in b245713</a> %H A265731 Anatoly E. Voevudko, <a href="/A261782/a261782.txt">Description of all powers in b261782</a> %H A265731 Wikipedia, <a href="https://en.wikipedia.org/wiki/Abc_conjecture">abc conjecture</a> %H A265731 Wikipedia, <a href="https://en.wikipedia.org/wiki/Fermat%E2%80%93Catalan_conjecture">Fermat-Catalan conjecture</a> %e A265731 8 = 2^3 = 2^2 + 2^2; 9 = 3^2 = 1^3 + 2^3; 16 = 4^2 = 2^3 + 2^3; etc. %o A265731 (PARI) A265731(lim,bflag=0)={my(Lcz=List(1),Lb=List(),czn,lczn,lbn,lim2=logint(lim, 2),lim3); %o A265731 for(z=2, lim2, lim3=sqrtnint(lim, z); for(C=2, lim3, listput(Lcz, C^z))); %o A265731 Lcz=Set(Lcz); lczn = #Lcz; if(lczn==0,return(-1)); %o A265731 for(i=1, lczn, for(j=i, lczn, czn=Lcz[i]+Lcz[j]; if(czn>lim, break); %o A265731 if(setsearch(Lcz, czn), listput(Lb, czn)))); listsort(Lb,1); lbn=#Lb; %o A265731 if(bflag, for(i=1,lbn,print(i , " ", Lb[i]))); if(!bflag,return(Vec(Lb))); } %o A265731 \\ _Anatoly E. Voevudko_, Nov 23 2015 %Y A265731 Cf. A000290, A245713, A261782, A264901, A265732. %K A265731 nonn,easy %O A265731 1,1 %A A265731 _Anatoly E. Voevudko_, Dec 14 2015