OFFSET
1,1
COMMENTS
Sequence seems to consist only of odd values.
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..761
MATHEMATICA
f[n_]:=DivisorSigma[1, n]; lst={}; Do[If[2*f[n]==f[n+1], AppendTo[lst, n]], {n, 9!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jul 22 2009 *)
PROG
(PARI) { n=0; for (m=1, 10^10, if (sigma(m+1) == 2*sigma(m), write("b067081.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, May 08 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 18 2002
EXTENSIONS
Terms added by Harry J. Smith, May 08 2010
STATUS
approved