Re: [Maxima-discuss] Fail to understand result of funcsolve

[Daniel V. <dan...@ya...>]

 Hi All,
I've opened a bug report: #4640 Erroneos result of funcsolve.
Daniel Volinski

    En lunes, 24 de noviembre de 2025, 22:17:31 GMT+2, Michel Talon <ta...@lp...> escribió:  
 
  
As a matter of fact the program bugs because at line 342 one has a division by zero due to the fact that product(%a, %l, lo, %n-1) vanishes since it is
 
the product of %l^2/(%l^2+2*l) starting from l=0.  The way to get out of this problem is to impose a condition such as f(1)=1, then the product starts at
 
%l=1.  This can be checked by inserting some prints.
 
 
solve_rec((n+1)*f[n]-(n-1)*f[n-1]=(n+1)/(n-1),f[n],f(1)=1);
 
yields after applying factor to the result:
 
f[n] = ('sum(((%j+1)*(%j+2))/%j,%j,1,n-1)+2)/(n*(n+1))$
 
Package Zeilberger doesn't seem to allow to compute the sum.
 
 
(%i16) GosperSum((%j+1)*(%j+2)/%j,%j,1,n-1);
 (%o16)                        NON_GOSPER_SUMMABLE
 
 
 Le 24/11/2025 à 17:06, Barton Willis via Maxima-discuss a écrit :product(%a, %l, lo, %n-1)
  
The share package solve_rec is also unable to handle your recursion:
 -- 
Michel Talon _______________________________________________
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