Checking correctness of A079300
David Wilson
davidwwilson at comcast.net
Sat Apr 1 00:25:17 CEST 2006
Ok, never mind.
My new program only counts Brauer chains (addition chains where every element is
the sum of the previous element and some element) whereas there are addition
chains which are not Brauer chains (some element is the sum of two elements
before the previous element).
The 9 minimal chains I listed in my previous post:
(1 2 4 8 12 13)
(1 2 4 8 9 13)
(1 2 4 6 12 13)
(1 2 4 6 7 13)
(1 2 4 5 9 13)
(1 2 3 6 12 13)
(1 2 3 6 7 13)
(1 2 3 5 10 13)
(1 2 3 5 8 13)
are all Brauer chains. However, there is an additional minimal chain that is
non-Brauer:
(1 2 4 5 8 13)
making 10 in all, hence A079300(13) = 10 is correct. I will modify my program
and see if it agrees.
Also, my earlier observation that A008297 counts addtion chains for n is wrong,
it counts Brauer chains.
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