%I #10 Jan 08 2024 09:01:18

%S 1,2,3,4,5,6,6,7,8,9,10,11,12,13,13,14,15,16,17,18,19,20,20,21,22,23,

%T 24,24,25,26,26,27,28,29,30,31,32,33,33,34,35,36,37,38,39,40,40,41,42,

%U 43,44,45,46,47,47,48,49,50,51,51,52,53,53,54,55,56

%N Number of positive integers <= n which are the sum of 3 squares.

%C Sequence is 2-regular.

%H J.-P. Allouche and J. Shallit, <a href="https://www.cs.uwaterloo.ca/~shallit/Papers/as0.ps">The ring of k-regular sequences</a>, preprint.

%H J.-P. Allouche and J. Shallit, <a href="https://doi.org/10.1016/0304-3975(92)90001-V">The ring of k-regular sequences</a>, Theoretical Computer Sci., Vol. 98 (1992), pp. 163-197.

%Y Partial sums of A071374 (with its zeroth term omitted).

%K nonn

%O 0,2

%A _N. J. A. Sloane_, Jun 12 2002