Az Eszterházy Károly Tanárképző Főiskola Tudományos Közleményei. 1994. Sectio Mathematicae. (Acta Academiae Paedagogicae Agriensis : Nova series ; Tom. 22)
GRYTCZUK, A., On a theorem of G. Baron and A. Schinzel
128 Aleksander Grytczuk 2. PROOF of the Theorem B. Let (4) S lf< 7 = Y^ (Xcr(l) +Z<r(2)) (^(1) + ' " ' + Z<r(p-1) ) crES p-i and (5) Sk,a - ^^(í) + xí(2)) ' " ' + 1" ^(p-i)) First we note that if p — l\k and k > p — 1 then k — (p—l)t + r, 1 < r < p—l and by Fermât 's theorem we obtain S k,a = Sr,a (mod p). Thus it suffices to prove (2) in the case k < p — 1. It is easy to see that for such k we have (6) x- = x a(i) (mod p) for somé a and i = 1, 2, • • •, p — 1. From (6) we obtain Sk,a= i Xcr(a{l)) +X a(a(2))) • • • { xa(a(l)) + (7) <r<=S p-i + "• + ^-1))) (mod p) By (7) and (1) it follows that (8) S k}( X = (x ail ) +'•• + x a{ p_ 1 )y~ 1 (mod p). Now by (8) and (6) we obtain — (arf + + (mod p) and (2) is pro ved. For the proof (3) we remark that k = (p — 1 )t and by Fermât 's theorem we obtain (9) S K< J = Y, l-2---(p-l) = (p-l)!(p-l)! (mod p) CR£S P-1 From (9) and Wilson's theorem we obtain S k,a = 1 (mod p) and the proof is finished.