Clojure functions to generate playable selections (a.k.a. prognoses)
for the lottery game Extra.

the extra grid is columns-first.
0 5 10  15  20
1 6 11  16  21
2 7 12  17  22
3 8 13  18  23
4 9 14  19  24

rules: there can be only 6 "F"s total in the whole grid.
there must be 3 Fs in the inner 3x3 grid,
  the other 3 Fs must be on the remaining 16 cells -- the frame.
any column (top - bottom), row (left - right) or diagonal
can only contain up to 2 Fs.

Start by running (-main) in the Leiningen REPL:

$ lein repl
nREPL server started on port 53690
REPL-y 0.1.10
Clojure 1.5.1
    (Leiningen messages elided)
extra-prognoses=> (-main)
"F;F;6;9;5;F;16;F;26;18;34;F;42;F;37;58;59;49;52;54;68;66;64;62;63"
[  F ][  F ][ 34 ][ 58 ][ 68 ]
[  F ][ 16 ][  F ][ 59 ][ 66 ]
[  6 ][  F ][ 42 ][ 49 ][ 64 ]
[  9 ][ 26 ][  F ][ 52 ][ 62 ]
[  5 ][ 18 ][ 37 ][ 54 ][ 63 ]

"F;F;14;4;9;F;24;F;17;19;42;43;F;32;39;48;F;46;49;60;62;68;74;72;70"
[  F ][  F ][ 42 ][ 48 ][ 62 ]
[  F ][ 24 ][ 43 ][  F ][ 68 ]
[ 14 ][  F ][  F ][ 46 ][ 74 ]
[  4 ][ 17 ][ 32 ][ 49 ][ 72 ]
[  9 ][ 19 ][ 39 ][ 60 ][ 70 ]

and so on.