

A039789


phi(n) is equal to the product of (the sum of prime factors and the sum of exponents) of n+1.


0




OFFSET

1,1


COMMENTS

No further terms up to 20,000,000.  Harvey P. Dale, Apr 19 2013


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

phi(62)=30, 63=3^2*7^1, (3+7)*(2+1)=30.


MATHEMATICA

epQ[n_]:=Module[{fi=Transpose[FactorInteger[n+1]]}, EulerPhi[n]== Total[ First[fi]]* Total[Last[fi]]]; Select[Range[1000], epQ] (* Harvey P. Dale, Apr 19 2013 *)


CROSSREFS

Cf. A000010, A039697.
Sequence in context: A141548 A146159 A187986 * A279882 A171064 A042313
Adjacent sequences: A039786 A039787 A039788 * A039790 A039791 A039792


KEYWORD

nonn


AUTHOR

Olivier Gérard


EXTENSIONS

Next term if it exists is greater than 1500000  Reiner Martin (reinermartin(AT)hotmail.com), May 20 2001


STATUS

approved



