OFFSET
1,3
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(20) = tau(20)*(20-tau(20)) = 6*(20-6) = 84.
MAPLE
with(numtheory): A076627:=n->tau(n)*(n-tau(n)): seq(A076627(n), n=1..100); # Wesley Ivan Hurt, Jul 25 2017
MATHEMATICA
#[[1]](#[[2]]-#[[1]])&/@Table[{DivisorSigma[0, n], n}, {n, 60}] (* Harvey P. Dale, May 06 2017 *)
PROG
(Haskell)
a076627 n = a000005 n * a049820 n -- Reinhard Zumkeller, Feb 06 2012
(PARI) a(n) = my(d = numdiv(n)); d*(n-d); \\ Michel Marcus, Jul 25 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, May 27 2003
EXTENSIONS
Wrong offset fixed by Reinhard Zumkeller, Feb 06 2012
STATUS
approved