English

Mixed sums of squares and triangular numbers (II)

Number Theory 2007-12-24 v5 Combinatorics

Abstract

For an integer xx let txt_x denote the triangular number x(x+1)/2x(x+1)/2. Following a recent work of Z. W. Sun, we show that every natural number can be written in any of the following forms with x,y,zZx,y,z\in\Z: x2+3y2+tz,x2+3ty+tz,x2+6ty+tz,3x2+2ty+tz,4x2+2ty+tz.x^2+3y^2+t_z, x^2+3t_y+t_z, x^2+6t_y+t_z, 3x^2+2t_y+t_z, 4x^2+2t_y+t_z. This confirms a conjecture of Sun.

Keywords

Cite

@article{arxiv.math/0505187,
  title  = {Mixed sums of squares and triangular numbers (II)},
  author = {Song Guo and Hao Pan and Zhi-Wei Sun},
  journal= {arXiv preprint arXiv:math/0505187},
  year   = {2007}
}
R2 v1 2026-07-22T17:19:11.022Z