%I #11 Nov 23 2019 02:38:26
%S 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,25,26,
%T 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,
%U 50,51,52,53,54
%N Numbers of the form x^2 + y^2 + z^3 + w^3 (x, y, z, w >= 0).
%C Conjecture: 23 is the only number not in this sequence.
%C Not the same as A004830: 239 is a term of this sequence but not of A004830. - _R. J. Mathar_ and _Joerg Arndt_, Jul 28 2012
%C There are no other missing numbers from 24 to 10^8. - _Giovanni Resta_, Oct 12 2019
%e 22 = 2^2 + 4^2 + 1^3 + 1^3, 22 is in this sequence.
%Y Cf. A001481, A004999, A022549, A022550, A022551, A022552.
%K nonn
%O 1,3
%A _Philippe Deléham_, Jul 20 2012