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A229709 Least sum of two squares that is a primitive root of the n-th prime. 2
1, 2, 2, 5, 2, 2, 5, 2, 5, 2, 13, 2, 13, 5, 5, 2, 2, 2, 2, 13, 5, 29, 2, 13, 5, 2, 5, 2, 10, 5, 29, 2, 5, 2, 2, 13, 5, 2, 5, 2, 2, 2, 29, 5, 2, 34, 2, 5, 2, 10, 5, 13, 13, 18, 5, 5, 2, 26, 5, 13, 5, 2, 5, 17, 10, 2, 29, 10, 2, 2, 5, 13, 10, 2, 2, 5, 2, 5, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Eric M. Schmidt, Table of n, a(n) for n = 1..10000

Christopher Ambrose, On the Least Primitive Root Expressible as a Sum of Two Squares, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 13, Paper A55, 2013.

EXAMPLE

a(4) = 5 as 5 = 2^2 + 1^2 is a primitive root mod 7 (the 4th prime).

PROG

(Sage) def A229709(n) : p = nth_prime(n); return next(i for i in PositiveIntegers() if i%p!=0 and mod(i, p).multiplicative_order() == p-1 and all(q%4 != 3 or e%2==0 for (q, e) in factor(i)))

CROSSREFS

Cf. A001481, A122028, A229710.

Sequence in context: A155679 A319771 A021448 * A242277 A241476 A309727

Adjacent sequences:  A229706 A229707 A229708 * A229710 A229711 A229712

KEYWORD

nonn

AUTHOR

Eric M. Schmidt, Sep 27 2013

STATUS

approved

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Last modified September 30 20:19 EDT 2020. Contains 337440 sequences. (Running on oeis4.)