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 A275747 #23 Jun 25 2021 23:16:50
%S A275747 4,114,1595,24195,190463,4613167,23815950,240951477,2448240688,
%T A275747 40379465440,258630935725,3044619003271,26232953378021,
%U A275747 264066033166293,3218396161633945,29248021240625765,302064442857973298,3027736057187540859,32207709908667683204
%N A275747 Largest integer which cannot be written as a sum of n-th powers of odd primes.
%C A275747 Except for n=6, only the powers of 3 primes are needed, namely 3^n, 5^n and 7^n, which leads to an ultra-fast O(n) execution time. I executed the algorithm in Greenberg (1988) with a PARI/GP program in only a few seconds for 1000 terms. - _Mike Oakes_, Aug 16 2016
%H A275747 Mike Oakes, <a href="/A275747/b275747.txt">Table of n, a(n) for n = 1..1000</a>
%H A275747 H. Greenberg, <a href="http://dx.doi.org/10.1016/0196-6774(88)90025-9">Solution to a linear diophantine equation for nonnegative integers</a>, Journal of Algorithms, 9 (1988), 343-353.
%e A275747 For n=2, 114 is the largest integer which cannot be written as a sum of squares of odd primes.
%t A275747 With[{prs=Prime[Range[2,5]]},Table[FrobeniusNumber[prs^n],{n,20}]] (* _Harvey P. Dale_, Sep 19 2018 *)
%Y A275747 Cf. A275746. For all primes, including 2, see A275743, A122615.
%K A275747 nonn
%O A275747 1,1
%A A275747 _Mike Oakes_, Aug 07 2016