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A004831 Numbers that are the sum of at most 2 nonzero 4th powers. 10
0, 1, 2, 16, 17, 32, 81, 82, 97, 162, 256, 257, 272, 337, 512, 625, 626, 641, 706, 881, 1250, 1296, 1297, 1312, 1377, 1552, 1921, 2401, 2402, 2417, 2482, 2592, 2657, 3026, 3697, 4096, 4097, 4112, 4177, 4352, 4721, 4802, 5392, 6497, 6561, 6562, 6577, 6642 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Apart from 0, 1, 2, there are no three consecutive terms up to 10^16. The first two consecutive terms not of the form n^4, n^4+1 are 3502321 = 25^4 + 42^4, 3502322 = 17^4 + 43^4. - Charles R Greathouse IV, Oct 17 2017
LINKS
MATHEMATICA
Reap[For[n = 0, n < 10000, n++, If[MatchQ[ PowersRepresentations[n, 2, 4], {{_, _}, ___}], Print[n]; Sow[n]]]][[2, 1]] (* Jean-François Alcover, Oct 30 2017 *)
PROG
(Haskell)
a004831 n = a004831_list !! (n-1)
a004831_list = [x ^ 4 + y ^ 4 | x <- [0..], y <- [0..x]]
-- Reinhard Zumkeller, Jul 15 2013
(PARI) is(n)=#thue(thueinit(z^4+1), n) \\ Ralf Stephan, Oct 18 2013
(PARI) list(lim)=my(v=List(), t); for(m=0, sqrtnint(lim\=1, 4), for(n=0, min(sqrtnint(lim-m^4, 4), m), listput(v, n^4+m^4))); Set(v) \\ Charles R Greathouse IV, Sep 28 2015
CROSSREFS
Subsequences include A003336, A000583 and A002645.
Sequence in context: A261617 A075376 A032935 * A342030 A368404 A217307
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 29 03:51 EDT 2024. Contains 371264 sequences. (Running on oeis4.)