English

A common $q$-analogue of two supercongruences

Number Theory 2020-03-17 v1 Combinatorics

Abstract

We give a qq-congruence whose specializations q=1q=-1 and q=1q=1 correspond to supercongruences (B.2) and (H.2) on Van Hamme's 1997 list: k=0(p1)/2(1)k(4k+1)Akp(1)(p1)/2(modp3)andk=0(p1)/2Aka(p)(modp2), \sum_{k=0}^{(p-1)/2}(-1)^k(4k+1)A_k\equiv p(-1)^{(p-1)/2}\pmod{p^3} \quad\text{and}\quad \sum_{k=0}^{(p-1)/2}A_k\equiv a(p)\pmod{p^2}, where p>2p>2 is prime, Ak=j=0k1(1/2+j1+j)3=126k(2kk)3for k=0,1,2,, A_k=\prod_{j=0}^{k-1}\biggl(\frac{1/2+j}{1+j}\biggr)^3=\frac1{2^{6k}}{\binom{2k}k}^3 \quad\text{for}\ k=0,1,2,\dots, and a(p)a(p) is the pp-th coefficient of (the weight 3 modular form) qj=1(1q4j)6q\prod_{j=1}^\infty(1-q^{4j})^6. We complement our result with a general common qq-congruence for related hypergeometric sums.

Keywords

Cite

@article{arxiv.1910.10932,
  title  = {A common $q$-analogue of two supercongruences},
  author = {Victor J. W. Guo and Wadim Zudilin},
  journal= {arXiv preprint arXiv:1910.10932},
  year   = {2020}
}

Comments

9 pages