OFFSET
1,1
COMMENTS
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[5300000], 4*DivisorSigma[1, #]==25*EulerPhi[#]&] (* Harvey P. Dale, May 09 2012 *)
PROG
(PARI) for( i=1, 1e9, sigma(i)*4-25*eulerphi(i) || print1(i", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht and M. F. Hasler, Sep 23 2009
STATUS
approved