Factorial equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg87123] Factorial equations*From*: Artur <grafix at csl.pl>*Date*: Tue, 1 Apr 2008 05:26:08 -0500 (EST)*References*: <200804010819.DAA11874@smc.vnet.net>*Reply-to*: grafix at csl.pl

Who know how is possible with use Mathematica solving equations involving factorials e.g Solve[n! + n == 726, n] My difficult problem to solving is x=n y=n! find function f(x,y) such f[1,1!]==1, f[2,2!]==2, f[3,3!]==5, f[4,4!]=59,f[5,5!]=246, f[6,6!]=1103, f[7,7!]=5247 values are generated by procedure ClearAll[f]; a = {}; Do[k = 0; Do[k = k + f[n] x^n, {n, 0, s}]; m = Resultant[k, D[k, x], x]; AppendTo[a, Length[m]], {s, 1, 8}]; a Who can help in find formula or do above procedure much quickest I will be greatfull ! Best wishes ARTUR

**References**:**Something very simple.....***From:*Steve Gray <stevebg@roadrunner.com>