%I A152676
%S A152676 3,8,13,17,31,32,30,50,46,55,75,91,76,98,100,105,129,93,162,112,183,122,
%T A152676 144,177,241,187,217,228,155,288,203,189,213,311,269,274,334,381,266,
%U A152676 392,254,382,348,413,301,286,489,439,483,553,516,476,578,423,487,504
%N A152676 a(n)=A002144(n)-A002314(n)
%C A152676 If we take 4 numbers : 1, A002314(n), A152676(n), A152680(n) then
%C A152676 multiplication table modulo A002144(n) is isomorphc with latin square:
%C A152676 1 2 3 4
%C A152676 2 4 1 3
%C A152676 3 1 4 2
%C A152676 4 3 2 1
%C A152676 and isomorphic with multiplication table of {1,I,-I,-1} where I is Sqrt[ 
               -1],
%C A152676 A152680(n) is isomorphic with -1, A002314(n) with I or -I and A152676(n) 
               vice versa -I or I.
%C A152676 1, A002314(n), A152676(n), A152680(n) are subfield of Galois Field [A002144(n)].
%t A152676 aa = {}; Do[If[Mod[Prime[n], 4] == 1, k = 1; While[ ! Mod[k^2 + 1, Prime[n]] 
               == 0, k++ ]; AppendTo[aa, Prime[n] - k]], {n, 1, 200}]; aa (*Artur 
               Jasinski*)
%Y A152676 A002144, A002314, A152680
%Y A152676 Sequence in context: A022762 A022807 A081766 this_sequence A010064 A133330 
               A095762
%Y A152676 Adjacent sequences: A152673 A152674 A152675 this_sequence A152677 A152678 
               A152679
%K A152676 nonn
%O A152676 1,1
%A A152676 Artur Jasinski (grafix(AT)csl.pl), Dec 10 2008