■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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