OFFSET
0,3
EXAMPLE
a(11) = 2. There are 2 positive divisors (1 and 3) of 12 which are coprime to 2. So a(12) = 2.
MAPLE
with(numtheory): a[0]:=1: for n from 1 to 140 do ct:=0: div:=divisors(n): for j from 1 to tau(n) do if igcd(div[j], a[n-1])=1 then ct:=ct+1 else ct:=ct: fi: od: a[n]:=ct: od: seq(a[n], n=0..140); # Emeric Deutsch, Apr 27 2007
A116204 := proc(nmax) local a, n, dvs, resl, d ; a := [1] ; while nops(a) < nmax do n := nops(a) ; dvs := numtheory[divisors](n) ; resl :=0 ; for d from 1 to nops(dvs) do if gcd(op(d, dvs), op(-1, a)) = 1 then resl := resl+1 ; fi ; od ; a := [op(a), resl] ; od ; RETURN(a) ; end: A116204(100) ; # R. J. Mathar, Apr 27 2007
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Apr 16 2007
EXTENSIONS
More terms from R. J. Mathar and Emeric Deutsch, Apr 27 2007
STATUS
approved