OFFSET
1,1
COMMENTS
Here 1 is not considered a squarefree number.
LINKS
Daniel Suteu, Table of n, a(n) for n = 1..90
FORMULA
a(n) = A005117(a(n-1)+1), a(1) = 2.
Limit_{n->infinity} a(n+1)/a(n) = zeta(2). - Daniel Suteu, Jul 07 2022
EXAMPLE
a(2) = 3 and the third squarefree number is 5 hence a(3) = 5.
a(4) = 7 hence a(5) = 11 is the 7th squarefree number (2,3,5,6,7,10,11...)
75381 is the 45822nd squarefree number.
MATHEMATICA
sqf = {}; Do[ If[ SquareFreeQ[n], sqf = Append[sqf, n]], {n, 2, 334000} ]; a[1] = 2; a[n_] := sqf[[ a[n - 1]]]; Table[ a[n], {n, 1, 26}].
a[1]=2; a[x_] := Part[t, a[x-1]] t=Flatten[Position[Table[Abs[MoebiusMu[w]], {w, 2, 35000}], 1]]+1; t1=Table[a[w], {w, 1, 21}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, May 22 2002
EXTENSIONS
More terms from Robert G. Wilson v and Labos Elemer, Jun 07 2002
a(27)-a(37) from Donovan Johnson, Oct 29 2010
STATUS
approved