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 A003336 Numbers that are the sum of 2 positive 4th powers. 77
 2, 17, 32, 82, 97, 162, 257, 272, 337, 512, 626, 641, 706, 881, 1250, 1297, 1312, 1377, 1552, 1921, 2402, 2417, 2482, 2592, 2657, 3026, 3697, 4097, 4112, 4177, 4352, 4721, 4802, 5392, 6497, 6562, 6577, 6642, 6817, 7186, 7857, 8192, 8962, 10001, 10016, 10081, 10256, 10625 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers k such that k = x^4 + y^4 has a solution in positive integers x, y. There are no squares in this sequence. - Altug Alkan, Apr 08 2016 As the order of addition doesn't matter we can assume terms are in nondecreasing order. - David A. Corneth, Aug 01 2020 LINKS Sean A. Irvine, Table of n, a(n) for n = 1..20000 (terms 1..1000 from T. D. Noe, terms 1001..10000 from David A. Corneth) A. Bremner and P. Morton, A new characterization of the integer 5906, Manuscripta Math. 44 (1983) 187-229; Math. Rev. 84i:10016. S. R. Finch, On a generalized Fermat-Wiles equation [broken link] Steven R. Finch, On  Generalized Fermat-Wiles Equation [From the Wayback Machine] Samuel S. Wagstaff, Jr., Equal Sums of Two Distinct Like Powers, J. Int. Seq., Vol. 25 (2022), Article 22.3.1. Eric Weisstein's World of Mathematics, Biquadratic Number. FORMULA {i: A216284(i) > 0}. - R. J. Mathar, Jun 04 2021 EXAMPLE From David A. Corneth, Aug 01 2020: (Start) 16378801 is in the sequence as 16378801 = 43^4 + 60^4. 39126977 is in the sequence as 39126977 = 49^4 + 76^4. 71769617 is in the sequence as 71769617 = 19^4 + 92^4. (End) MATHEMATICA nn=12; Select[Union[Plus@@@(Tuples[Range[nn], {2}]^4)], # <= nn^4&] (* Harvey P. Dale, Dec 29 2010 *) Select[Range@ 11000, Length[PowersRepresentations[#, 2, 4] /. {0, _} -> Nothing] > 0 &] (* Michael De Vlieger, Apr 08 2016 *) PROG (PARI) list(lim)=my(v=List()); for(x=1, sqrtnint(lim\=1, 4), for(y=1, min(sqrtnint(lim-x^4, 4), x), listput(v, x^4+y^4))); Set(v) \\ Charles R Greathouse IV, Apr 24 2012; updated July 13 2024 (PARI) T=thueinit('x^4+1, 1); is(n)=#thue(T, n)>0 && !issquare(n) \\ Charles R Greathouse IV, Feb 26 2017 (Python) def aupto(lim): p1 = set(i**4 for i in range(1, int(lim**.25)+2) if i**4 <= lim) p2 = set(a+b for a in p1 for b in p1 if a+b <= lim) return sorted(p2) print(aupto(10625)) # Michael S. Branicky, Mar 18 2021 CROSSREFS 5906 is the first term in A060387 but not in this sequence. Cf. A020897. Cf. A088687 (2 distinct 4th powers). A###### (x, y): Numbers that are the form of x nonzero y-th powers. 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). Cf. A000583 (4th powers). Sequence in context: A162622 A078164 A060387 * A344187 A212740 A212742 Adjacent sequences: A003333 A003334 A003335 * A003337 A003338 A003339 KEYWORD nonn,easy,changed AUTHOR N. J. A. Sloane STATUS approved

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Last modified July 23 17:49 EDT 2024. Contains 374553 sequences. (Running on oeis4.)