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Numbers which are the sum or difference of two fifth powers.
2

%I #40 Aug 01 2023 15:19:19

%S 0,1,2,31,32,33,64,211,242,243,244,275,486,781,992,1023,1024,1025,

%T 1056,1267,2048,2101,2882,3093,3124,3125,3126,3157,3368,4149,4651,

%U 6250,6752,7533,7744,7775,7776,7777,7808,8019,8800,9031,10901,13682,15552,15783,15961

%N Numbers which are the sum or difference of two fifth powers.

%H Charles R Greathouse IV, <a href="/A247099/b247099.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) << n^(5/2). Can this be improved?

%e 31 = 2^5 - 1^5, 32 = 2^5 + 0^5, 33 = 2^5 + 1^5.

%t Union[Flatten[{Total[#],Abs[#[[2]]-#[[1]]]}&/@Tuples[Range[0,10]^5,2]]] (* _Harvey P. Dale_, Mar 30 2015 *)

%o (PARI) T=thueinit('z^5+1);

%o is(n)=n==0 || #thue(T, n)>0

%Y Cf. A000584, A004842, A004831, A181124.

%K nonn

%O 1,3

%A _Charles R Greathouse IV_, Nov 29 2014