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Numbers n such that there is at least one x<n such that phi(x)sigma(x)=phi(n)sigma(n).

0

`%I #7 Mar 30 2012 18:38:57
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`%S 6,22,33,42,44,56,57,62,66,68,76,78,82,96,102,108,110,114,124,132,135,
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`%T 136,138,140,145,148,154,159,165,168,174,176,182,183,186,189,198,204,
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`%U 205,213,216,220,222,224,228,231,234,246,254,258,264,267,270,282,285
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`%N Numbers n such that there is at least one x<n such that phi(x)sigma(x)=phi(n)sigma(n).
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`%o (PARI) for(n=1,500,if(prod(i=1,n-1, sigma(n)*eulerphi(n)-sigma(i)*eulerphi(i))==0,print1(n,",")))
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`%K easy,nonn
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`%O 1,1
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`%A _Benoit Cloitre_, Apr 28 2002
`