OFFSET
1,1
COMMENTS
Chowla's function (A048050) = sum of divisors of n except 1 and n.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MAPLE
with(numtheory):
[seq(`if`((sigma(i)-i-1) mod tau(i) <> 0, i, print( )), i=1..1000)];
MATHEMATICA
cfQ[n_]:=!Divisible[DivisorSigma[1, n]-1-n, DivisorSigma[0, n]]; Select[ Range[ 150], cfQ] (* Harvey P. Dale, Jul 22 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 19 2000
STATUS
approved