■ベキ和の周期性(その5)

ベキ和

Sk(n)=1^k+2^k+3^k+・・・+n^k

についても類似の結果が得られるに違いない。

a^k (mod3)の場合について調べてみると・・・

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a :0,1,2,3,4,5,6,7,8,9

a :0,1,2,0,1,2,0,1,2,0

a^2:0,1,1,0,1,1,0,1,1,0

a^3:0,1,2,0,1,2,0,1,2,0

a^4:0,1,1,0,1,1,0,1,1,0

a^5:0,1,2,0,1,2,0,1,2,0

a^6:0,1,1,0,1,1,0,1,1,0

a^7:0,1,2,0,1,2,0,1,2,0

a^8:0,1,1,0,1,1,0,1,1,0

a^9:0,1,2,0,1,2,0,1,2,0

S1(n)=1,0,0,1,0,0,・・・(00になるまで周期3)

S2(n)=1,2,2,0,1,1,2,2,0,0,・・・(00になるまで周期9=3^2)

S3(n)=1,0,0,1,0,0,・・・=S1(n)

S4(n)=1,2,2,0,1,1,2,2,0,0,・・・=S2(n)

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