OFFSET
1,3
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
MAPLE
a[1]:=1: for n from 2 to 75 do b[n]:=[seq(a[gcd(a[k], n-1)], k=1..n-1)]: a[n]:=sum(b[n][j], j=1..nops(b[n])) od: seq(a[n], n=1..75);
MATHEMATICA
a[1] = 1; a[n_] := a[n] = Plus @@ a /@ GCD[Table[a[i], {i, n - 1}], n - 1]; Table[ a[n], {n, 64}] (* Robert G. Wilson v, Dec 09 2004 *)
PROG
(PARI) first(n)=my(v=vector(n)); v[1]=1; for(i=1, n-1, v[i+1]=sum(k=1, i, v[gcd(v[k], i)])); v \\ Charles R Greathouse IV, Apr 05 2016
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