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arXiv · 2007.10910

Almost universal ternary sums of pentagonal numbers

Hai-Liang Wu·Li-Yuan Wang
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Abstract

For each integer $x$, the $x$-th generalized pentagonal number is denoted by $P_5(x)=(3x^2-x)/2$. Given odd positive integers $a,b,c$ and non-negative integers $r,s$, we employ the theory of ternary quadratic forms to determine when the sum $aP_5(x)+2^rbP_5(y)+2^scP_5(z)$ represents all but finitely many positive integers.

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Hai-Liang Wu, Li-Yuan Wang. 2020-07-21. Almost universal ternary sums of pentagonal numbers. https://arxiv.org/abs/2007.10910

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