Re: Extract Integers

*To*: mathgroup at smc.vnet.net*Subject*: [mg131432] Re: Extract Integers*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sun, 21 Jul 2013 21:43:17 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130721082357.762536A19@smc.vnet.net>

equ = Series[Exp[x], {x, 0, 5}] // Normal; {Cases[equ, _Integer, Infinity], Cases[equ, Rational[n_, d_] :> {n, d}, Infinity]} // Flatten // Union {1, 2, 3, 4, 5, 6, 24, 120} Cases[equ, i_Integer | Rational[n_, d_] :> Sequence[i, n, d], Infinity] // Union {1, 2, 3, 4, 5, 6, 24, 120} Bob Hanlon On Sun, Jul 21, 2013 at 4:23 AM, Dana DeLouis <dana01 at icloud.com> wrote: > Hi. I've run out of ideas. Does anyone know the proper way to extract > all the integers from the following simplified version of a larger problem > I'm working on? > > equ=Series[Exp[x],{x,0,5}] //Normal > > 1+x+x^2/2+x^3/6+x^4/24+x^5/120 > > When trying to extract all the integers, I understand numbers like 120 are > part of Rational[1,120] > > equ //FullForm > > << Not shown here >> > > I thought looking at all LevelSpec was the solution, but apparently not. > > Cases[equ, _Integer, Infinity] > {1,2,3,4,5} > > (* Or *) > > Position[equ, _Integer, Infinity] > {{1},{3,2,2},{4,2,2},{5,2,2},{6,2,2}} > > Extract[equ, %] > {1,2,3,4,5} > > Both ways extract from the numerator, but I just can't seem to extract the > {2,6,24,120} inside the denominator. > Does anyone know the proper way? > Thanks in advance. :>~ > > Dana > Mac & Math 9 > > >

**References**:**Extract Integers***From:*Dana DeLouis <dana01@icloud.com>