OFFSET
1,2
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
Do[s=(DivisorSigma[1, n]+DivisorSigma[1, n+1])/ DivisorSigma[1, 2*n+1]; If[ !Greater[s, 1], Print[n]], {n, 1, 10000000}]
PROG
(PARI) is(n)=sigma(n)+sigma(n+1)<=sigma(2*n+1) \\ Charles R Greathouse IV, Feb 14 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Feb 16 2004
EXTENSIONS
New name from Charles R Greathouse IV, Feb 14 2013
STATUS
approved