■完全数と親和数の公式(その5)

 12000<n(n+1)/2<16000

 12000<n(n+1)(n+2)/6<16000

 12000<n(n+1)(n+2)(n+3)/24<16000

 12000<n(n+1)(n+2)(n+3)(n+4)/120<16000

についても調べてみよう.

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[1]n(n+1)/2,[155,178]→NG

[2]n(n+1)(n+2)/6,[41,44]→NG

[3]n(n+1)(n+2)(n+3)/24,[22,23]→NG

[4]n(n+1)(n+2)(n+3)(n+4)/120,[16,16]→NG

[5]n(n+1)(n+2)(n+3)(n+4)(n+5)/720,[12,12]→NG

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