[math-fun] Add no digit of n to n
Hello Math-Fun, What is the last term of the sequence starting with "1" and obeying the rule: "Add to n the smallest positive integer sharing no digit with n" Sequence should begin like this : 1,3,4,5,6,7,8,9,10,12,15,17,19,21,24,25.... Best, E.
123456978, after 65627501 iterations. What did we do before computers could do millions of pointless calculations for us?... --Michael On 12/10/06, Eric Angelini <Eric.Angelini@kntv.be> wrote:
Hello Math-Fun,
What is the last term of the sequence starting with "1" and obeying the rule:
"Add to n the smallest positive integer sharing no digit with n"
Sequence should begin like this :
1,3,4,5,6,7,8,9,10,12,15,17,19,21,24,25....
Best,
E.
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So this finite sequence has 65627501 terms? Or maybe 65627502? Jim On 12/10/06, Michael Kleber <michael.kleber@gmail.com> wrote:
123456978, after 65627501 iterations.
What did we do before computers could do millions of pointless calculations for us?...
--Michael
On 12/10/06, Eric Angelini <Eric.Angelini@kntv.be> wrote:
Hello Math-Fun,
What is the last term of the sequence starting with "1" and obeying the rule:
"Add to n the smallest positive integer sharing no digit with n"
Sequence should begin like this :
1,3,4,5,6,7,8,9,10,12,15,17,19,21,24,25....
Best,
E.
James Buddenhagen <jbuddenh@gmail.com> wrote:
So this finite sequence has 65627501 terms? Or maybe 65627502? Jim
I suppose this sequence is best 0-indexed: the 0th term is 1, the 1st term is f(1)=3, the second term is f^2(1)=4. In that case, the last term is f^65627501(1) = 123456978. Calculated in Mma, by the way: f[x_] := x + Module[{y=Complement[Range[9],IntegerDigits[x]]}, If[Length[y]>0,Min[y],0]] I can handle one-liners even with a 7-month-old in my arms... --Michael
On 12/10/06, Michael Kleber <michael.kleber@gmail.com> wrote:
123456978, after 65627501 iterations.
What did we do before computers could do millions of pointless calculations for us?...
--Michael
On 12/10/06, Eric Angelini <Eric.Angelini@kntv.be> wrote:
Hello Math-Fun,
What is the last term of the sequence starting with "1" and obeying the rule:
"Add to n the smallest positive integer sharing no digit with n"
Sequence should begin like this :
1,3,4,5,6,7,8,9,10,12,15,17,19,21,24,25....
Best,
E.
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-- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.
participants (4)
-
Eric Angelini -
James Buddenhagen -
Michael Kleber -
Paul R. Pudaite