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%I #10 Nov 07 2015 17:39:06
%S 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,
%T 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,
%U 2,5,17,10,2,29,10,2,2,5,13,10,2,2,5,2,5,13
%N Least sum of two squares that is a primitive root of the n-th prime.
%H Eric M. Schmidt, <a href="/A229709/b229709.txt">Table of n, a(n) for n = 1..10000</a>
%H Christopher Ambrose, <a href="http://www.emis.de/journals/INTEGERS/papers/n55/n55.Abstract.html">On the Least Primitive Root Expressible as a Sum of Two Squares</a>, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 13, Paper A55, 2013.
%e a(4) = 5 as 5 = 2^2 + 1^2 is a primitive root mod 7 (the 4th prime).
%o (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)))
%Y Cf. A001481, A122028, A229710.
%K nonn
%O 1,2
%A _Eric M. Schmidt_, Sep 27 2013
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