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 A123207 #18 Aug 07 2025 15:00:08
%S A123207 61,89,181,401,673,773,2089,2557,12497,33049,78857,98057,98929,135329,
%T A123207 268921,338323,390721,531989,552241,554233,794881,1954097,2165089,
%U A123207 4204961,5967161,8389141,9765757,11423429,17200609,33555061,35835953,40356523,48829699,87863309,268457417
%N A123207 Primes of the form x^y + y^z + z^x, for x,y,z > 1.
%H A123207 Andrew Howroyd, <a href="/A123207/b123207.txt">Table of n, a(n) for n = 1..1000</a>
%H A123207 Andrew Howroyd, <a href="/A123207/a123207.txt">Table of n, x, y, z, a(n) for n = 1..1000</a>
%e A123207 61 = 5^2 + 2^2 + 2^5.
%e A123207 89 = 4^3 + 3^2 + 2^4.
%t A123207 Take[Select[Intersection[Flatten[Table[x^y+y^z+z^x,{x,2,60},{y,2,60},{z,2,60}]]],PrimeQ[ # ]&],40]
%o A123207 (PARI) upto(lim) = { my(L=List()); for(x=2, logint(lim,2), for(y=2, min(x,logint(lim,x)), for(z=2, min(x-1,logint(lim,y)), my(t=x^y+y^z+z^x); if(t<=lim && isprime(t), listput(L,t)) ))); Set(L) } \\ _Andrew Howroyd_, Aug 06 2025
%Y A123207 Cf. A094133 (primes of form x^y + y^x), A386892.
%K A123207 nonn
%O A123207 1,1
%A A123207 _Alexander Adamchuk_, Oct 04 2006
%E A123207 a(32)-a(35) from _Michael S. Branicky_, Jul 11 2025