[seqfan] Re: A175388(?)

[Hans Havermann]

Douglas McNeil:

> If I've done everything correctly, I find instead a(17) = 578 *  
> 10**(196)-1
> = 577999...9.

Agreed. And this might make a(18) = 5889 *  
10 
^ 
71358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358024691358022 
  - 1 (same caveat).

Zak:

> %e A175388 a(0)=1 because 1 -> 1 (0 iterations)
> %e A175388 a(1)=2 because 2 -> 4 (1 iteration)
> %e A175388 a(2)=11 because 11 -> 2 -> 4 (2 iterations)
> %e A175388 a(3)=23 because 23 -> 13 -> 10 -> 1 (3 iterations)
> %e A175388 a(4)=19 because 19 -> 82 -> 20 -> 4 (4 iterations).

How about a(0)=1 (0 iterations)... Drop the "because 1 -> 1". And the  
a(4)=19 line needs to be fixed: 19 -> 82 -> 68 -> 100 -> 1