|
Search: id:A065819
|
|
|
| A065819 |
|
4*EulerPhi[n] = 3*DivisorSigma[1,n]. |
|
+0
5
|
|
| 7, 209, 10013, 11687, 12857, 17537, 27577, 28067, 700321, 770431, 1321189, 1542281, 1681861, 1963039, 2282641, 2313961, 2664259, 3308041, 3709057, 3859207, 3929761, 4315751, 4380541, 4561381, 5193001, 5331001, 5576519
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,65
|
|
EXAMPLE
|
For m=10013, Phi[m]=8640,Sigma[m]=11520, 34560=4*Phi=3*Sigma.
|
|
MATHEMATICA
|
Do[s = 4*EulerPhi[n]-3*DivisorSigma[1, n]; If[Equal[s, 0], Print[n]], {n, 1, 10000000}]
|
|
PROGRAM
|
(PARI) { n=0; for (m=1, 10^9, if (4*eulerphi(m) == 3*sigma(m), write("b065819.txt", n++, " ", m); if (n==65, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 31 2009]
|
|
CROSSREFS
|
Cf. A000010, A000203, A062699
Sequence in context: A124988 A128680 A157775 this_sequence A061028 A045760 A046033
Adjacent sequences: A065816 A065817 A065818 this_sequence A065820 A065821 A065822
|
|
KEYWORD
|
easy,nonn,new
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu), Nov 23 2001
|
|
|
Search completed in 0.002 seconds
|
