OFFSET
1,3
COMMENTS
a(n) is 2 if n is an even integer >= 4.
a(7937) has more than 1000 decimal digits. - Chai Wah Wu, Aug 30 2014
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..7936
EXAMPLE
a(1)=1, a(2)=1, a(3)=2, a(4)=2, a(6)=2, a(7)=14 and a(8)=2 are the terms, prior to a(9), which are coprime to 9. So a(9) = 1 +1 +2 +2 +2 +14 +2 = 24.
MATHEMATICA
a[1] = 1; a[n_] := a[n] = Plus @@ (a /@ Select[Range[n - 1], GCD[ a[ # ], n] == 1 &]); Table[ a[n], {n, 56}] (* Robert G. Wilson v, Jul 31 2004 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jul 28 2004
EXTENSIONS
Edited and extended by Robert G. Wilson v, Jul 31 2004
STATUS
approved