OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
MATHEMATICA
f[x_] := DivisorSigma[1, x]; t=Table[f[w+1]*f[w], {w, 1, 128}]
Times@@@Partition[DivisorSigma[1, Range[50]], 2, 1] (* Harvey P. Dale, May 21 2014 *)
PROG
(PARI) a(n)=sigma(n)*sigma(n+1) \\ Charles R Greathouse IV, Feb 14 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Labos Elemer, May 21 2003
STATUS
approved