[seqfan] Cumulative multiplication
Eric Angelini
Eric.Angelini at kntv.be
Sat Apr 18 12:21:56 CEST 2015
Hello SeqFans,
take an integer N like 2188;
create this (repeated) pattern:
2 1 8 8 2 1 8 8 2 1 8 8 2 1 8 8 ...
Insert the "multiply sign" everywhere:
2*1*8*8*2*1*8*8*2*1*8*8*2*1*8*8*...
Look at the partial cumulative
multiplications -- if N reappears,
you have a hit:
2*1=2
2*1*8=16
2*1*8*8=128
2*1*8*8*2=256
2*1*8*8*2*1=256
2*1*8*8*2*1*8=2048
2*1*8*8*2*1*8*8=16384
...
We have obviously a miss here.
What would be the first hit for N > 10?
Best,
É.
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