Steiner systems ๐(5,6,๐ฃ) with ๐ฃ=72 and 84
Steiner systems ๐(5,6,๐ฃ) with ๐ฃ=72 and 84
It is proved that there are precisely 4204 pairwise non-isomorphic Steiner systems <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper S left-parenthesis 5 comma 6 comma 72 right-parenthesis"> <mml:semantics> <mml:mrow> <mml:mi>S</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mn>5</mml:mn> <mml:mo>,</mml:mo> <mml:mn>6</mml:mn> <mml:mo>,</mml:mo> <mml:mn>72</mml:mn> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">S(5,6,72)</mml:annotation> </mml:semantics> </mml:math> </inline-formula> invariant under the group <inline-formula content-type="math/mathml"> <mml:math โฆ