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A355597
a(1) = 2. For n > 1, a(n) = smallest prime q such that q^(a(n-1)-1) == 1 (mod a(n-1)^2).
5
2, 5, 7, 19, 127, 911, 7331, 167149, 387749, 17153317, 432383657, 10459192927
OFFSET
1,1
COMMENTS
Is this an increasing sequence or does it enter a cycle?
PROG
(PARI) seq(start, terms) = my(x=start, i=1); print1(start, ", "); while(1, forprime(q=1, , if(Mod(q, x^2)^(x-1)==1, print1(q, ", "); x=q; i++; if(i >= terms, break({2}), break))))
seq(2, 20) \\ Print initial 20 terms of sequence
CROSSREFS
Row n = 1 of A249162.
Sequence in context: A096146 A041583 A143915 * A309542 A327322 A160820
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Jul 09 2022
STATUS
approved