[seqfan] Re: [math-fun] Triangular+Triangular = Factorial

[Georgi Guninski]

On Tue, Sep 14, 2010 at 10:11:09AM -0600, Richard Guy wrote:
> 
> 4.  The first values of  z  about which I am ignorant
> are  z = 71, 74, 80, 81, 93, 99, 100, ...
>

attaching my and some of Douglas McNeil's factorizations.

summary, check attached file for factorizations (gzipped due to list,
limitations, also available at:
http://stefan.guninski.com/seq/guyres2.txt ):

71 is not a solution (Douglas McNeil)
74 is not a solution
80 solution, 3 factors
81 solution, 4 factors
93 - unknown to me, trying it with EC
99 solution, 6 factors
100 is not a solution

the rest go:
101(-),102(+5),103(-),104(-),105(-),106(-),108(-),110(-),111(-),112(-),113(-),115(-),116(-),117(-),118(+6),119(-),120(-),121(-),122(-),123(-),124(-),127(-),128(-),129(+2) ... more, check attached factors