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Message Posted: Thu, 15 Sep 2005 @ 16:49:56 GMT

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You can use logarithms.

Ivo Spaleny

SQL code:

     /* prepare lookup */
     create volatile table tmp_NumberList(X integer not null) unique primary
     index (X);

     BT;

     /*fill lookup*/
     insert tmp_NumberList(X) values (0);
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B ;
     insert tmp_NumberList(X) select MX+X+1 from tmp_NumberList A cross join
     (select max(X) MX from tmp_NumberList ) B
     where MX+X+1<=170 /* 171 .. overflow of FLOAT/DOUBLE factorial */
     ;

     /* select factorials */
     select A.X,COALESCE(EXP(SUM(LN(B.X (FLOAT)))),1)
     from  tmp_NumberList A
     left join   tmp_NumberList B on B.X between 1 and A.X
     where A.X<=170   /* 171! ... overflow of FLOAT/DOUBLE factorial */
     group by A.X
     order by 1;

     ET;

     /* clean up */
     drop table tmp_NumberList;

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