|
|
A067573
|
|
Numbers such that Sigma(Phi(k))/Sigma(k) > Sigma(Phi(j))/Sigma(j) for all k > j.
|
|
2
|
|
|
2, 3, 5, 7, 13, 31, 37, 61, 181, 241, 421, 1009, 1201, 1321, 1801, 2161, 2521, 7561, 12601, 15121, 30241, 55441, 110881, 278263, 332641, 555911, 666917, 722473, 1443853, 2165407, 3607403, 4324321, 7212581, 8654539, 10817761, 21631147
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
a = 0; Do[b = DivisorSigma[1, EulerPhi[n]]/DivisorSigma[1, n]; If[b > a, a = b; Print[n]], {n, 2, 10^7}]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|