For any m,n∈N={0,1,2…}, the truncated hypergeometric series m+1Fm is defined by m+1Fm[x0x1y1……xmymz]n=k=0∑n(y1)k⋯(ym)k(x0)k(x1)k⋯(xm)k⋅k!zk, where (x)k=x(x+1)⋯(x+k−1) is the Pochhammer symbol. Let p be an odd prime. For α,z∈Zp with ⟨−α⟩p≡0(mod2), where ⟨x⟩p denotes the least nonnegative residue of x modulo p for any x∈Zp, we mainly prove the following congruence motivated by Orr's identity: 2F1[21α23−21α1z]p−12F1[21α21−21α1z]p−1≡3F2[α2−α1211z]p−1(modp2). As a corollary, for any positive integer b with p≡±1(modb) and ⟨−1/b⟩p≡0(mod2), we deduce that k=0∑p−1(b2k+b−1)4k(k2k)(k−1/b)(k1/b−1)≡0(modp2). This confirms a conjectural congruence of the second author.
@article{arxiv.2103.02951,
title = {A parametric congruence motivated by Orr's identity},
author = {Chen Wang and Zhi-Wei Sun},
journal= {arXiv preprint arXiv:2103.02951},
year = {2023}
}
Comments
8 pages, accepted by Journal of Difference Equations and Applications