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 A003380 #42 Apr 27 2024 20:03:03
%S A003380 2,257,512,6562,6817,13122,65537,65792,72097,131072,390626,390881,
%T A003380 397186,456161,781250,1679617,1679872,1686177,1745152,2070241,3359232,
%U A003380 5764802,5765057,5771362,5830337,6155426,7444417,11529602,16777217,16777472,16783777,16842752
%N A003380 Numbers that are the sum of 2 nonzero 8th powers.
%H A003380 David A. Corneth, <a href="/A003380/b003380.txt">Table of n, a(n) for n = 1..10000</a> (first 5833 terms from R. J. Mathar, replacing an earlier b-file that was missing terms)
%e A003380 From _David A. Corneth_, Aug 01 2020: (Start)
%e A003380 274893519322337 is in the sequence as 274893519322337 = 58^8 + 59^8.
%e A003380 357707312890625 is in the sequence as 357707312890625 = 50^8 + 65^8.
%e A003380 2590188068194497 is in the sequence as 2590188068194497 = 57^8 + 84^8. (End)
%p A003380 A003380 := proc(nmax::integer)
%p A003380 local a, x,x8,y,y8 ;
%p A003380 a := {} ;
%p A003380 for x from 1 do
%p A003380 x8 := x^8 ;
%p A003380 if 2*x8 > nmax then
%p A003380 break;
%p A003380 end if;
%p A003380 for y from x do
%p A003380 y8 := y^8 ;
%p A003380 if x8+y8 > nmax then
%p A003380 break;
%p A003380 end if;
%p A003380 if x8+y8 <= nmax then
%p A003380 a := a union {x8+y8} ;
%p A003380 end if;
%p A003380 end do:
%p A003380 end do:
%p A003380 sort(convert(a,list)) ;
%p A003380 end proc:
%p A003380 nmax := 20000000000000000 ;
%p A003380 L:= A003380(nmax) ;
%p A003380 LISTTOBFILE(L,"b003380.txt",1) ; # _R. J. Mathar_, Aug 01 2020
%t A003380 Total/@Tuples[Range[8]^8,2]//Union (* _Harvey P. Dale_, Apr 04 2017 *)
%o A003380 (PARI) list(lim)=my(v=List(), x8); for(x=1, sqrtnint(lim\=1, 8), x8=x^8; for(y=1, min(sqrtnint(lim-x8, 8), x), listput(v, x8+y^8))); Set(v) \\ _Charles R Greathouse IV_, Aug 22 2017
%Y A003380 Subsequence of A004875.
%Y A003380 Cf. A155468 (2 distinct 8th).
%Y A003380 A###### (x, y): Numbers that are the form of x nonzero y-th powers.
%Y A003380 Cf. A000404 (2, 2), A000408 (3, 2), A000414 (4, 2), A003072 (3, 3), A003325 (3, 2), A003327 (4, 3), A003328 (5, 3), A003329 (6, 3), A003330 (7, 3), A003331 (8, 3), A003332 (9, 3), A003333 (10, 3), A003334 (11, 3), A003335 (12, 3), A003336 (2, 4), A003337 (3, 4), A003338 (4, 4), A003339 (5, 4), A003340 (6, 4), A003341 (7, 4), A003342 (8, 4), A003343 (9, 4), A003344 (10, 4), A003345 (11, 4), A003346 (12, 4), A003347 (2, 5), A003348 (3, 5), A003349 (4, 5), A003350 (5, 5), A003351 (6, 5), A003352 (7, 5), A003353 (8, 5), A003354 (9, 5), A003355 (10, 5), A003356 (11, 5), A003357 (12, 5), A003358 (2, 6), A003359 (3, 6), A003360 (4, 6), A003361 (5, 6), A003362 (6, 6), A003363 (7, 6), A003364 (8, 6), A003365 (9, 6), A003366 (10, 6), A003367 (11, 6), A003368 (12, 6), A003369 (2, 7), A003370 (3, 7), A003371 (4, 7), A003372 (5, 7), A003373 (6, 7), A003374 (7, 7), A003375 (8, 7), A003376 (9, 7), A003377 (10, 7), A003378 (11, 7), A003379 (12, 7), A003380 (2, 8), A003381 (3, 8), A003382 (4, 8), A003383 (5, 8), A003384 (6, 8), A003385 (7, 8), A003387 (9, 8), A003388 (10, 8), A003389 (11, 8), A003390 (12, 8), A003391 (2, 9), A003392 (3, 9), A003393 (4, 9), A003394 (5, 9), A003395 (6, 9), A003396 (7, 9), A003397 (8, 9), A003398 (9, 9), A003399 (10, 9), A004800 (11, 9), A004801 (12, 9), A004802 (2, 10), A004803 (3, 10), A004804 (4, 10), A004805 (5, 10), A004806 (6, 10), A004807 (7, 10), A004808 (8, 10), A004809 (9, 10), A004810 (10, 10), A004811 (11, 10), A004812 (12, 10), A004813 (2, 11), A004814 (3, 11), A004815 (4, 11), A004816 (5, 11), A004817 (6, 11), A004818 (7, 11), A004819 (8, 11), A004820 (9, 11), A004821 (10, 11), A004822 (11, 11), A004823 (12, 11), A047700 (5, 2).
%K A003380 nonn,easy
%O A003380 1,1
%A A003380 _N. J. A. Sloane_