OFFSET
1,3
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..200
EXAMPLE
6 is the largest squarefree divisor of a(12) = 96. So a(13) = 6 + a(11) = 65.
MAPLE
with(numtheory): A007947 := proc(n) local i, t1, t2; t1 := ifactors(n)[2]; t2 := mul(t1[i][1], i=1..nops(t1)); end: a:=proc(n) if n=1 or n=2 then 1 else A007947(a(n-1))+a(n-2) fi end: seq(a(n), n=1..25); # Emeric Deutsch, Jul 24 2006
MATHEMATICA
nxt[{a_, b_}]:={b, a+Max[Select[Divisors[b], SquareFreeQ]]}; NestList[nxt, {1, 1}, 50][[All, 1]] (* Harvey P. Dale, Jan 21 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jul 23 2006
EXTENSIONS
More terms from Emeric Deutsch, Jul 24 2006
More terms from R. J. Mathar, May 18 2007
STATUS
approved