# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a022555 Showing 1-1 of 1 %I A022555 #15 Nov 06 2012 12:38:05 %S A022555 3,4,5,6,7,10,11,12,13,14,15,17,18,19,20,21,22,23,24,25,26,29,30,31, %T A022555 32,33,34,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,55,56, %U A022555 57,58,59,60,61,62,63,66,67,68,69,70,71,73,74,75,76,77 %N A022555 Positive integers that are not the sum of two nonnegative cubes. %C A022555 Omits the positive cubes (A000578) since m^3 = 0^3 + m^3, so is different from A057903. %H A022555 T. D. Noe, Table of n, a(n) for n=1..10000 %H A022555 Index entries for sequences related to sums of cubes %p A022555 read transforms; cub := series(add(q^(n^3),n=0..100),q,1000001); t1 := series(cub^2,q,2000); t2 := POWERS(t1,q,2000); COMPl(t2); %t A022555 r[n_] := Reduce[x >= 0 && y >= 0 && n == x^3 + y^3, {x, y}, Integers]; Select[ Range[80], r[#] === False &] (* _Jean-François Alcover_, Nov 06 2012 *) %t A022555 Select[Range@100,PowersRepresentations[#,2,3]=={}&] (* A much faster solution given by _Giovanni Resta_, Nov 06 2012 *) %Y A022555 Complement of A004999. Cf. A004825, A022561, A022566, A057903, A000578. %K A022555 nonn %O A022555 1,1 %A A022555 _N. J. A. Sloane_. %E A022555 Edited by _N. J. A. Sloane_, Sep 28 2007 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE