MinT - Best Known (161−121, 161, s)-Nets in Base 4

Best Known (161−121, 161, s)-Nets in Base 4

(161−121, 161, 56)-Net over F₄ — Constructive and digital

Digital (40, 161, 56)-net over F₄, using

t-expansion [i] based on digital (33, 161, 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]

(161−121, 161, 75)-Net over F₄ — Digital

Digital (40, 161, 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]

(161−121, 161, 171)-Net over F₄ — Upper bound on s (digital)

There is no digital (40, 161, 172)-net over F₄, because

1 times m-reduction [i] would yield digital (40, 160, 172)-net over F₄, but
- extracting embedded orthogonal array [i] would yield linear OA(4¹⁶⁰, 172, F₄, 120) (dual of [172, 12, 121]-code), but
  - constructionÂ Y1 [i] would yield
    1. linear OA(4¹⁵⁹, 166, F₄, 120) (dual of [166, 7, 121]-code), but
      - residual code [i] would yield linear OA(4³⁹, 45, F₄, 30) (dual of [45, 6, 31]-code), but
        â€œDaâ€ bound on codes from Brouwerâ€™s database [i]
    2. OA(4¹², 172, S₄, 6), but
      - discarding factors would yield OA(4¹², 156, S₄, 6), but
        the Rao or (dual) Hamming bound shows that MÂ â‰¥ 16 866019 > 4¹² [i]

(161−121, 161, 264)-Net in Base 4 — Upper bound on s

There is no (40, 161, 265)-net in base 4, because

1 times m-reduction [i] would yield (40, 160, 265)-net in base 4, but
- the generalized Rao bound for nets shows that 4^mÂ â‰¥ 2 153627 852648 971862 282865 424584 699451 257238 836756 826347 434727 870668 924638 433233 403750 780707 837888 > 4¹⁶⁰ [i]