OFFSET
1,1
LINKS
Ben Kane and Zhi-Wei Sun, On almost universal mixed sums of squares and triangular numbers, arXiv:0808.2761
MATHEMATICA
r[k_] := Reduce[x >= 0 && y >= 0 && z >= 0 && k == 4x^2 + 4y^2 + z(z+1)/2, {x, y, z}, Integers];
Reap[For[k=1, k <= 1000, k++, If[r[k]===False, Print[k]; Sow[k]]]][[2, 1]] (* Jean-François Alcover, Aug 31 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 05 2008
STATUS
approved