quiz

[N. J. A. Sloane]

Dear Yasutoshi,


The trouble is that I can only give a small numbers of terms 
of any sequence.

Therefore it is necessary to have a starting point.
--------------------------------------------------

For the Fibonacci numbers

  0 1 1 2 3 5 8 13 21 ...

there is an obvious place to begin.


For your sequence:

    "an example of periodic 1/4-sigma sequence : the period = 25
6943520030720  5386209454080  6389772480000  7665533854902  5756592291840
5657834203560  6382469882880  7938550287360  9055131471360   9256155068160
11798498589696  12316979136000  13937317954560  18314063179776
18071888486400  20136798781440  18850467643392  16492422758400
15699547839573  6635615891520  7400619883008  6494644316160  8009835724800
9317732578770  7847237806128"

where does it begin?


With best wishes

Neil Sloane