OFFSET
1,5
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
a(8) = 6. The remainders when 8 is divided by the coprime numbers 1, 3, 5 and 7 are 0, 2, 3 and 1, whose sum = 6.
MATHEMATICA
a[n_] := Sum[If[GCD[i, n]>1, 0, Mod[n, i]], {i, 1, n-1}]
Table[Total[Mod[n, #]&/@Select[Range[n-1], CoprimeQ[#, n]&]], {n, 70}] (* Harvey P. Dale, May 22 2012 *)
PROG
(PARI) a(n)=sum(i=1, n-1, if(gcd(n, i)==1, n%i)) \\ Charles R Greathouse IV, Jul 17 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jan 29 2002
EXTENSIONS
Edited by Dean Hickerson, Feb 15 2002
STATUS
approved