A101806 - OEIS

%I #10 Jul 24 2022 23:06:28

%S 3059,3197,3473,3887,4439,5129,5957,6923,8027,9269,10649,24334,24472,

%T 24886,25576,26542,27784,29302,31096,33166,35512,38134,41032,44206,

%U 47656,51382,55384,59662,64216,69046,74152,79534,82179,82593,83421

%N Numbers which are the sum of two positive cubes and divisible by 23.

%H Vincenzo Librandi, <a href="/A101806/b101806.txt">Table of n, a(n) for n = 1..1000</a>

%t upto[n_] := Block[{t}, Union@ Reap[ Do[If[Mod[t = x^3 + y^3, 23] == 0, Sow@t], {x, n^(1/3)}, {y, Min[x, (n - x^3)^(1/3)]}]][[2, 1]]]; upto[84000] (* _Giovanni Resta_, Jun 12 2020 *)

%t Select[Total/@Tuples[Range[50]^3,2],Divisible[#,23]&]//Union (* _Harvey P. Dale_, Jul 24 2022 *)

%K nonn,easy

%O 1,1

%A Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Jan 27 2005