OFFSET
1,3
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..10000
EXAMPLE
The largest prime dividing 12 is 3. So a(13) = a(12) + a(3) = 64 + 2 = 66.
MAPLE
with(numtheory): a[1]:=1:a[2]:=1:for n from 2 to 55 do a[n+1]:=a[n]+a[factorset(n)[nops(factorset(n))]] od: seq(a[n], n=1..55); # Emeric Deutsch, Mar 07 2007
MATHEMATICA
a128215[1] = 1; a128215[2] = 1;
a128215[n_] := a128215[n] = a128215[n-1] + a128215[First[Last[FactorInteger[n-1]]]];
Array[a128215, 48] (* 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