1997 spring 1+2+3=6 (i.e. 1 old ewe, 5 lambs,1* * 6 sheep).
1998 spring 1+5+5= 1 1 (that is, there are 1 old ewes, five lambs last year and five this year, and one * * *1).
1999 spring 1+5+5 = 16 (that is, there are 1 old ewes, five in the year before last, five in last year, plus five this year,1* *16).
Spring 20001+5+5 = 21ditto.
200 1+5+5+(1+3) * 5 = 21+4 * 5 = 41(2001,with the original1. )
In the spring of 2002, 21+(1+3) * 5+(1+3) * 5 = 21+1* 5 = 76 (/kloc )
In the spring of 2003, 21+(1+3) * 5+(1+3+3) * 5 = 21+21.
Spring 200421+(1+3) * 5+(1+3+3) * 5+(1+3+3) * 5+(1+3+3).
In the spring of 2005, 21+20+35+50+65+80 = 271(according to the above rule, one more number 15 is added to the last one at a time).
In the spring of 2006, the rule of 21+20+35+50+65+80+95 = 361is the same as above.
Spring 2007 21+20+35+50+65+80+95+10 = 471.
Spring 2009 February1+20+35+50+65+80+95+10+125 = 596.
20 10 spring 21+20+35+50+65+80+95+10+125+140 = 736.
At the end of 20 10, there were 736 sheep.