A316348 a(n) is the smallest k > 1 such that gcd(k, m^k - m) = 1 for all m = 2,...,n.
35, 35, 77, 77, 143, 143, 143, 143, 299, 299, 323, 323, 323, 323, 437, 437, 667, 667, 667, 667, 899, 899, 899, 899, 899, 899, 1457, 1457, 1739, 1739, 1739, 1739, 1739, 1739, 1763, 1763, 1763, 1763, 2021, 2021, 2491, 2491, 2491, 2491, 3127, 3127, 3127, 3127, 3127
Offset: 2
Keywords
Links
- Michel Marcus, Table of n, a(n) for n = 2..306
Programs
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PARI
isok(k, n)= {for (m=2, n, if (gcd(k, m^k - m) != 1, return (0));); return(1);} a(n) = {my(k=2); while (! isok(k, n), k++); k;} \\ Michel Marcus, Aug 13 2018
Formula
Conjecture: a(n) ~ n^2.
Extensions
More terms from Michel Marcus, Aug 13 2018
Comments