

A316348


a(n) is the smallest k > 1 such that gcd(k, m^k  m) = 1 for all m = 2,...,n.


1



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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

2,1


COMMENTS

Conjecture: all the terms are in A121707.
GCD(n, a(n)) = 1. a(n) is odd.
Is a(n) squarefree?
a(n+1) >= a(n) by definition. (End)
It seems that a(prime(n+1)1) > a(prime(n)1) for n > 1.  Thomas Ordowski, Aug 13 2018


LINKS



FORMULA

Conjecture: a(n) ~ n^2.


PROG

(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


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



