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A new formulation of the law of octic reciprocity for primes ¢ ‰ ±3(mod8) and its consequencesDOI: 10.1155/s0161171282000532 Keywords: quartic and octic residuacity criteria , A.E. Western's formula , binary quadratic forms. Abstract: Let p and q be odd primes with q ¢ ‰ ±3(mod8), p ¢ ‰ 1(mod8)=a2+b2=c2+d2 and with the signs of a and c chosen so that a ¢ ‰ c ¢ ‰ 1(mod4). In this paper we show step-by-step how to easily obtain for large q necessary and sufficient criteria to have ( ¢ ’1(q ¢ ’1)/2q(p ¢ ’1)/8 ¢ ‰ (a ¢ ’b)d/ac)j(modp) for j=1, ¢ € |,8 (the cases with j odd have been treated only recently [3] in connection with the sign ambiguity in Jacobsthal sums of order 4. This is accomplished by breaking the formula of A.E. Western into three distinct parts involving two polynomials and a Legendre symbol; the latter condition restricts the validity of the method presented in section 2 to primes q ¢ ‰ 3(mod8) and significant modification is needed to obtain similar results for q ¢ ‰ ±1(mod8). Only recently the author has completely resolved the case q ¢ ‰ 5(mod8), j=1, ¢ € |,8 and a sketch of the method appears in the closing section of this paper.
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