MinT - Best Known (251−207, 251, s)-Nets in Base 4

Best Known (251−207, 251, s)-Nets in Base 4

(251−207, 251, 56)-Net over F₄ — Constructive and digital

Digital (44, 251, 56)-net over F₄, using

t-expansion [i] based on digital (33, 251, 56)-net over F₄, using
- net from sequence [i] based on digital (33, 55)-sequence over F₄, using
  - Niederreiterâ€“Xing sequence constructionÂ II/III [i] based on function field F/F₄ with g(F) = 33 and N(F) ≥ 56, using
    - F₅ from the tower of function fields by GarcÃa and Stichtenoth over F₄ [i]

(251−207, 251, 75)-Net over F₄ — Digital

Digital (44, 251, 75)-net over F₄, using

t-expansion [i] based on digital (40, 251, 75)-net over F₄, using
- net from sequence [i] based on digital (40, 74)-sequence over F₄, using
  - Niederreiterâ€“Xing sequence constructionÂ II/III [i] based on function field F/F₄ with g(F) = 40 and N(F) ≥ 75, using
    - Drinfeld modules of rank 1 [i]

(251−207, 251, 185)-Net over F₄ — Upper bound on s (digital)

There is no digital (44, 251, 186)-net over F₄, because

71 times m-reduction [i] would yield digital (44, 180, 186)-net over F₄, but
- extracting embedded orthogonal array [i] would yield linear OA(4¹⁸⁰, 186, F₄, 136) (dual of [186, 6, 137]-code), but
  - constructionÂ Y1 [i] would yield
    1. linear OA(4¹⁷⁹, 183, F₄, 136) (dual of [183, 4, 137]-code), but
      - Griesmer bound [i]
    2. linear OA(4⁶, 186, F₄, 3) (dual of [186, 180, 4]-code or 186-cap in PG(5,4)), but
      - discarding factors / shortening the dual code would yield linear OA(4⁶, 160, F₄, 3) (dual of [160, 154, 4]-code or 160-cap in PG(5,4)), but
        1 times Hill recurrence [i] would yield linear OA(4⁵, 42, F₄, 3) (dual of [42, 37, 4]-code or 42-cap in PG(4,4)), but
        41 is the largest size of a cap in PG(4,Â 4) [i]

(251−207, 251, 190)-Net in Base 4 — Upper bound on s

There is no (44, 251, 191)-net in base 4, because

64 times m-reduction [i] would yield (44, 187, 191)-net in base 4, but
- extracting embedded orthogonal array [i] would yield OA(4¹⁸⁷, 191, S₄, 143), but
  - the (dual) Plotkin bound shows that MÂ â‰¥ 153914 086704 665934 422965 000391 185991 426092 731525 255651 046673 021110 334850 669910 978950 836977 558144 201721 900890 587136 / 3 > 4¹⁸⁷ [i]