Let p be an odd prime and let a be a positive integer. In this paper we investigate the sum , where h and m are p-adic integers with m ≢ 0 (mod p). For example, we show that if h ≢ 0 (mod p) and , then , where (·/·) denotes the Jacobi symbol. Here is another remarkable congruence: If then .
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm127-1-3, author = {Zhi-Wei Sun}, title = {On sums of binomial coefficients modulo p$^2$}, journal = {Colloquium Mathematicae}, volume = {126}, year = {2012}, pages = {39-54}, zbl = {1266.11035}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm127-1-3} }
Zhi-Wei Sun. On sums of binomial coefficients modulo p². Colloquium Mathematicae, Tome 126 (2012) pp. 39-54. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm127-1-3/