[seqfan] Re: Summer sequence boot camp : adding digits to the right... and more

[Erich Friedman]

> ***Question (1):
>   What are the first 100 integers with no predecessors?

0, and the three digit numbers where the middle digit is at least as large as the other two, are the first ones.

> ***Question (2)
>   What are the first 100 "looping integers"?

only 15 cycles (36 looping integers) are known: 

99(a+1) --> 181a --> 99(a+1)   [where 0≤a≤8]

3333(a+1) --> 666(a+4) --> 12121a -->3333(a+1)   [where 0≤a≤5]

see  http://www2.stetson.edu/~efriedma/mathmagic/0200.html  for more info.

erich