■eの連分数展開(その7)

  e=[2;1,2,1,1,4,1,1,6,1,1,8,1,1,10,1,1,12,1,1,14,1,1,16,・・・]

  e=[2;1,2,1,1,4,1,1,6,1,・・・,1,2n,1,・・・]

a1=2

a3m-1=1

a3m=2m

a3m+1=1と書ける

p0=1,q0=0

p1=2,q1=1

p2=p1+p0=3,q2=q1+q0=1

p3=2p2+p1=8,q3=2q2+q1=3

p4=p3+p2=11,q4=q3+q2=4

p5=p4+p3=19,q5=q4+q3=7

p6=4p5+p4=87,q6=4q5+q4=32

[参]吉田信夫「数学の不思議にきづく勘所、技術評論社

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f0(x)=1/0!・x^0(x-1)^1,f1(x)=1/0!・x^1(x-1)^0

f2(x)=1/1!・x^1(x-1)^1,f3(x)=1/1!・x^1(x-1)^2

f4(x)=1/1!・x^2(x-1)^1,f5(x)=1/2!・x^2(x-1)^2

f2(x)=1/2!・x^2(x-1)^3,f7(x)=1/2!・x^3(x-1)^3

f8(x)=1/3!・x^3(x-1)^3,・・・

f3m(x)=1/m!・x^m(x-1)^m+1

f3m+1(x)=1/m!・x^m+1(x-1)^m+1

f3m+2(x)=1/(m+1)!・x^m+1(x-1)^m+1

∫(0,∞)exp(-x)fn(x)dx=qn

e∫(1,∞)exp(-x)fn(x)dx=pn

pn/qn→e

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p3m-1=p3m-2+p3m-3,q3m-1=q3m-2+q3m-3

p3m=2mp3m-1+p3m-2,q3m=2mq3m-1+q3m-2

p3m+1=p3m+p3m-1,q3m+1=q3m+q3m-1

f3m+1=(x)=f3m(x)+f3m-1(x)

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