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Design parameters are 2-(21,5,1), b=21

Blocks of the design are:
0168i 02cfg 0349b 057hk 0adej 1279j 13dgh 145ac 1befk 238ak 24ehi 256bd 35fij 367ce 46gjk 478df 589eg 69afh 7abgi 8bchj 9cdik
The design is simple

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Auto’m group order is 120960

All non-isomorphic minimal defining sets are:

0168i 02cfg 0349b 057hk 1279j 13dgh 145ac 238ak 24ehi
Size=9 |Aut|=6
0168i 02cfg 057hk 0adej 1279j 13dgh 145ac 238ak 24ehi
Size=9 |Aut|=12
0168i 0349b 057hk 0adej 1279j 13dgh 145ac 238ak 24ehi
Size=9 |Aut|=2
0349b 057hk 0adej 13dgh 145ac 1befk 238ak 24ehi
Size=8 |Aut|=48
0168i 057hk 0adej 1279j 13dgh 145ac 238ak 24ehi 35fij
Size=9 |Aut|=4

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Size Count
—- —–
8 1
9 4

Only 5 (non-isomorphic) minimal defining sets
Totally 123480 (inequivalent) minimal defining sets

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