[seqfan] Re: Rank of a prime (Collatz/Syracuse)

[Robert G. Wilson, v]

Edwin,

PrimePi[222312455509]=8862793537.

    I use Mathematica and this one took me just 1.451 seconds. 
Mathematica runs out of
its ability for the initial integer of 40.

Bob.

Edwin Clark wrote:

>On Sun, 1 Feb 2009, Jacques Tramu wrote:
>
>  
>
>>So  the question is :
>>does any sequence terminates in "1"  or with the" 15 23 9 22 15 loop" ?
>>or 25 - ea(25)  is 25 33 25
>>    
>>
>
>
>How about 14? 14->14
>
>The first number I had trouble with was 18. The problem there is 
>eventually it gets to the prime 222312455509 and I have difficulty 
>figuring out pi(222312455509).
>
>
>
>
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