×

On the sequence \(n ! \bmod p\). (English) Zbl 07835935

The paper presents some new results on the sequence \(n!\pmod p\). Let \({\mathcal A}_p=\{n! \pmod p, n\in [0,p-1]\}\). The authors show that \(\#{\mathcal A}_p\ge ({\sqrt{2}}+o(1)){\sqrt{p}}\) as \(p\to\infty\). This improves the result \(\#{\mathcal A}_p\ge ({\sqrt{41/24}}+o(1)){\sqrt{p}}\) for \(p\to\infty\) of V. C. García [Bol. Soc. Mat. Mex., III. Ser. 13, No. 1, 1–6 (2007; Zbl 1195.11010)]. The authors also study a short interval version of the problem. Let \({\mathcal A}_N=\{n!: L\le n\le L+N\}\). They show that if \(N\gg p^{7/8}\log p\), then \(\#{\mathcal A}_N\ge (1+o(1)){\sqrt{p}}\) as \(p\to\infty\). Finally, they revisit a result from M. Z. Garaev et al. [Trans. Am. Math. Soc. 356, No. 12, 5089–5102 (2004; Zbl 1060.11046)] where it was shown that for all integers \(a\) there is a solution to the congruence \(a\equiv n_1! n_2!\cdots n_7!\pmod p\) with \(n_0:=\max\{n_i: 1\le i\le 7\}=O(p^{11/12+\varepsilon})\) as \(p\to\infty\) and improve the exponent \(11/12\) to \(6/7\).

MSC:

11N56 Rate of growth of arithmetic functions
11L03 Trigonometric and exponential sums (general theory)
11B65 Binomial coefficients; factorials; \(q\)-identities

References:

[1] Aubry, Y. and Perret, M.: A Weil theorem for singular curves. In Arithmetic, geometry and coding theory (Luminy, 1993), pp. 1-7. De Gruyter Proceedings in Mathematics, Berlin, 1996. · Zbl 0873.11037 · doi:10.1515/9783110811056.1
[2] Broughan, K. A. and Barnett, A. R.: On the missing values of nŠ mod p. J. Ramanujan Math. Soc. 24 (2009), no. 3, 277-284. · Zbl 1205.11027
[3] Chalk, J. H. H. and Smith, R. A.: On Bombieri’s estimate for exponential sums. Acta Arith. 18 (1971), 191-212. · Zbl 0219.12021 · doi:10.4064/aa-18-1-191-212
[4] Chang, M.-C.: Sparsity of the intersection of polynomial images of an interval. Acta Arith. 165 (2014), no. 3, 243-249. · Zbl 1308.11085 · doi:10.4064/aa165-3-3
[5] Cilleruelo, J., Garaev, M. Z., Ostafe, A. and Shparlinski, I. E.: On the concentration of points of polynomial maps and applications. Math. Z. 272 (2012), no. 3-4, 825-837. · Zbl 1285.11027 · doi:10.1007/s00209-011-0959-7
[6] Cobeli, C., Vâjâitu, M. and Zaharescu, A.: The sequence nŠ .mod p/. J. Ramanujan Math. Soc. 15 (2000), no. 2, 135-154. · Zbl 0962.11005
[7] Fried, M.: On a conjecture of Schur. Michigan Math. J. 17 (1970), no. 1, 41-55. · Zbl 0169.37702 · doi:10.1307/mmj/1029000374
[8] Garaev, M. Z. and Hernández, J.: A note on nŠ modulo p. Monatsh. Math. 182 (2017), no. 1, 23-31. · Zbl 1364.11137 · doi:10.1007/s00605-015-0867-8
[9] Garaev, M. Z., Luca, F. and Shparlinski, I. E.: Character sums and congruences with nŠ. Trans. Amer. Math. Soc. 356 (2004), no. 12, 5089-5102. · Zbl 1060.11046 · doi:10.1090/S0002-9947-04-03612-8
[10] García, V. C.: On the value set of nŠ mŠ modulo a large prime. Bol. Soc. Mat. Mexicana (3) 13 (2007), no. 1, 1-6. · Zbl 1195.11010
[11] García, V. C.: Representations of residue classes by product of factorials, binomial coefficients and sum of harmonic sums modulo a prime. Bol. Soc. Mat. Mexicana (3) 14 (2008), no. 2, 165-175. · Zbl 1244.11020
[12] Guy, R. K.: Unsolved problems in number theory. Second edition. Problem Books in Mathem-atics, Unsolved Problems in Intuitive Mathematics I, Springer, New York, 1994. · Zbl 0805.11001 · doi:10.1007/978-1-4899-3585-4
[13] Klurman, O. and Munsch, M.: Distribution of factorials modulo p. J. Théor. Nombres Bor-deaux 29 (2017), no. 1, 169-177. · Zbl 1429.11037 · doi:10.5802/jtnb.974
[14] Lang, S. and Weil, A.: Number of points of varieties in finite fields. Amer. J. Math. 76 (1954), no. 4, 819-827. · Zbl 0058.27202 · doi:10.2307/2372655
[15] Lev, V. F.: Permutations in abelian groups and the sequence nŠ .mod p/. · Zbl 1112.20048 · doi:10.1016/j.ejc.2005.03.003
[16] European J. Combin. 27 (2006), no. 5, 635-643. · Zbl 1112.20048
[17] Rokowska, B. and Schinzel, A.: Sur un probléme de M. Erdős. Elem. Math. 15 (1960), 84-85. · Zbl 0089.26603
[18] Schmidt, W. M.: Absolutely irreducible equations f .x; y/ D 0. In Equations over finite fields, an elementary approach, pp. 92-133. Lecture Notes in Mathematics 536, Springer, Berlin, Heidelberg, 1976. · Zbl 0329.12001 · doi:10.1007/BFb0080441
[19] Trudgian, T.: There are no socialist primes less than 10 9 . Integers 14 (2014), article no. A63, 4 pp. · Zbl 1336.11009
[20] Turnwald, G.: On Schur’s conjecture. J. Austral. Math. Soc. Ser. A 58 (1995), no. 3, 312-357. · Zbl 0834.11052 · doi:10.1017/s1446788700038349
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.