OFFSET
1,3
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..10000
EXAMPLE
The smallest prime dividing 12 is 2. So a(13) = a(12) + a(2) = 52 + 1 = 53.
MAPLE
with(numtheory): a[1]:=1:a[2]:=1:for n from 2 to 55 do a[n+1]:=a[n]+a[factorset(n)[1]] od: seq(a[n], n=1..55); # Emeric Deutsch, Mar 07 2007
MATHEMATICA
a128216[1] = 1; a128216[2] = 1;
a128216[n_] := a128216[n] = a128216[n-1] + a128216[First[First[FactorInteger[n-1]]]];
Array[a128216, 49] (* data *) (* Hartmut F. W. Hoft, Mar 08 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Feb 19 2007
EXTENSIONS
More terms from Emeric Deutsch, Mar 07 2007
STATUS
approved