OFFSET
1,2
REFERENCES
D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, p. 14.
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(9) = 12 because sigma(9) = 13 and phi(13) = 12.
MAPLE
with(numtheory); A062401:=n->phi(sigma(n)); seq(A062401(n), n=1..50); # Wesley Ivan Hurt, Apr 07 2014
MATHEMATICA
Table[EulerPhi[DivisorSigma[1, n]], {n, 1, 80}] (* Carl Najafi, Aug 16 2011 *)
PROG
(PARI) vector(150, n, eulerphi(sigma(n)))
(PARI) for (n=1, 10000, write("b062401.txt", n, " ", eulerphi(sigma(n))) ) \\ Harry J. Smith, Aug 07 2009
(Haskell)
a062401 = a000010 . a000203 -- Reinhard Zumkeller, Jan 04 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 08 2001
STATUS
approved