OFFSET
0,5
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
FORMULA
MAPLE
MATHEMATICA
DivisorSigma[0, #+1]-DivisorSigma[0, #-1]&/@Prime[Range[80]] (* Harvey P. Dale, Nov 01 2011 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Leroy Quet, Oct 08 2008
EXTENSIONS
More terms from R. J. Mathar and Ray Chandler, Oct 10 2008
STATUS
approved