RecurrenceTable warning

*To*: mathgroup at smc.vnet.net*Subject*: [mg102430] RecurrenceTable warning*From*: green tea <cetech07 at gmail.com>*Date*: Sun, 9 Aug 2009 06:05:11 -0400 (EDT)

Hello, I'm using Mathematica 7.0.1. This example is in documentation center. In[1]:= RecurrenceTable[{a[n + 1] == 3 a[n], a[1] == 7}, a, {n, 1, 5}] Out[1]= {7, 21, 63, 189, 567} I added a[n]==b[n]. In[2]:= RecurrenceTable[{b[n] == a[n], a[n + 1] == 3 a[n], a[1] == 7}, {a, b}, {n, 1, 5}] Out[2]= {{7, 7}, {21, 21}, {63, 63}, {189, 189}, {567, 567}} it works well. but when I simply swapped a with b, a warning occured. In[3]:= RecurrenceTable[{a[n] == b[n], b[n + 1] == 3 b[n], b[1] == 7}, {b, a}, {n, 1, 5}] During evaluation of In[3]:= Inverse::matsq: Argument {{1/4,1,-1}, {1/4,0,1}} at position 1 is not a non-empty square matrix. >> Out[3]= {{7, 7}, {21, 21}, {63, 63}, {189, 189}, {567, 567}}

**Follow-Ups**:**Re: RecurrenceTable warning***From:*dkapadia@wolfram.com