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 A274173 #11 Jun 17 2016 00:30:42 %S A274173 609076,9745216,28998521,36924641 %N A274173 Numbers n such that n is not divisible by 5 and n^k is of the form a^2 + b^4 for all k not divisible by 4. %C A274173 Numbers n such that n, n^2 and n^3 is in A111925 and n is not divisible by 5. %C A274173 Since there cannot be fourth power in A111925, this sequence focuses on the values of k that is not divisible by 4 in definition. %e A274173 609076 is a term because 609076 = 710^2 + 18^4, 609076^2 = 581940^2 + 424^4, 609076^3 = 475342920^2 + 676^4 and it is not divisible by 5. %o A274173 (PARI) isA111925(n) = for(b=1, sqrtnint(n-1, 4), if(issquare(n-b^4), return(1))); 0; %o A274173 isok(n) = n%5 != 0 && isA111925(n) && isA111925(n^2) && isA111925(n^3); %Y A274173 Cf. A111925. %K A274173 nonn,more %O A274173 1,1 %A A274173 _Altug Alkan_, Jun 12 2016