OFFSET
1,3
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
MAPLE
a[1]:=1: for n from 2 to 70 do b[n]:=[seq(a[gcd(k, a[n-1])], k=1..n-1)]: a[n]:=sum(b[n][j], j=1..nops(b[n])) od: seq(a[n], n=1..70);
MATHEMATICA
a[1] = 1; a[n_] := a[n] = Plus @@ a /@ GCD[Range[n - 1], a[n - 1]]; Table[ a[n], {n, 62}] (* Robert G. Wilson v, Dec 09 2004 *)
PROG
(GAP) a:=[1];; for n in [2..65] do a[n]:=Sum([1..n-1], k->a[Gcd(k, a[n-1])]); od; a; # Muniru A Asiru, Oct 21 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Dec 06 2004
EXTENSIONS
More terms from Emeric Deutsch and Robert G. Wilson v, Dec 09 2004
STATUS
approved