Wartime recurrence

In mathematics, it is not unusual to define an entity using a recurrence relation. 
For example, in defining powers of a positive integer:
       The 2nd power of  7  may be defined as  7  x  7¹ ;
               the 3rd power of  7  may be defined as  7  times  7², 
              and the 4th power is  7  times  7³,
              and, in general, for any positive integer n,  7ⁿ⁺¹  =  7  x  7ⁿ. 

Several weeks ago I attended a reading of fine poetry here in Silver Spring at the Nora School  -- a reading that featured DC-area poets Judith Bowles, Luther Jett, and David McAleavey.  I was delighted to hear in "Recessional" -- one of the poems presented that evening by Jett -- the mathematical pattern of recurrence, building stepwise  with a potentially infinite number of steps (as with the powers of 7, above) into a powerful poem.  I include it below:  

Your Favorite Number

In the Washington, DC area's Beltway Poetry Quarterly, edited by Kim Roberts, I recently found this lively number-poem by Pennsylvania poet Barbara DeCesare in the Summer 2012 issue that features poets in the federal government.  Enjoy.

     Your Favorite Number   by Barbara DeCesare

     I hope you have a damn good reason
     because when you let a number like that in,
     it’ll turn on you so fast.
     36: spine on spine, a grudge,
     a house divided, half-sisters,
     or the twins,