A081213 - OEIS

A081213

Let r(n,k) = if k=0 then n, else r(A081210(n),k-1), then a(n)=r(n, A081212(n)).

1, 2, 3, 3, 5, 6, 7, 7, 7, 10, 11, 7, 13, 14, 15, 15, 17, 14, 19, 15, 21, 22, 23, 21, 23, 26, 26, 21, 29, 30, 31, 31, 33, 34, 35, 21, 37, 38, 39, 35, 41, 42, 43, 33, 35, 46, 47, 35, 47, 46, 51, 39, 53, 39, 55, 47, 57, 58, 59, 35, 61, 62, 47, 62, 65, 66, 67, 51, 69, 70, 71, 47, 73

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OFFSET

1,2

COMMENTS

A081210(a(n)) = a(n).

Different from A081211.

a(n) = A081211(n) for n<84 = A131072(1); a(A131072(n)) <> A081211(A131072(n)). - Reinhard Zumkeller, Jun 13 2007

LINKS

R. Zumkeller, Table of n, a(n) for n = 1..10000

MAPLE

A081212r := proc(n, k)

option remember ;

if k =0 then

else

procname(A081210(n), k-1) ;

end if;

end proc:

A081212 := proc(n)

local i ;

for i from 0 do

if A081212r(n, i) = A081212r(n, i+1) then

return i ;

end if;

end do:

end proc:

A081213 := proc(n)

A081212r(n, A081212(n)) ;

end proc:

seq(A081213(n), n=1..84) ; # R. J. Mathar, May 25 2023

MATHEMATICA

gsf[n_] := For[k = n, True, k--, If[SquareFreeQ[k], Return[k]]];

A081210[n_] := (cnt++; Times @@ gsf /@ Power @@@ FactorInteger[n]);

A081212[n_] := (cnt = 0; FixedPoint[A081210, n]; cnt - 1);

r[n_, k_] := r[n, k] = If[k == 0, n, r[A081210[n], k - 1]];

a[n_] := r[n, A081212[n]];

Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Sep 12 2023 *)

CROSSREFS

Cf. A081210, A081211, A081212, A081214.

Cf. A131072.

Sequence in context: A262882 A187043 A081211 * A081210 A285719 A070321

Adjacent sequences: A081210 A081211 A081212 * A081214 A081215 A081216

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 10 2003

STATUS

approved