More Results on the Existence of Simple BIBDs with Number of Elements a Prime Power
We study the existence of simple (q, k, λ) BIBDs when the number of elements is a prime powerqand {c 1,c 2} ⋂ {1, 2} is not empty, wherec 1= gcd(k, q− 1) andc 2= gcd(k− 1,q− 1). We show that in many situations the necessary conditions λ(q− 1) ≡ 0 mod (k− 1), λq(q− 1) ≡ 0 modk(k− 1), and λ ≤ ( k − 2...
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Published in | Taiwanese journal of mathematics Vol. 20; no. 3; pp. 523 - 543 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
Mathematical Society of the Republic of China
01.06.2016
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Subjects | |
Online Access | Get full text |
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Summary: | We study the existence of simple (q, k, λ) BIBDs when the number of elements is a prime powerqand {c
1,c
2} ⋂ {1, 2} is not empty, wherec
1= gcd(k, q− 1) andc
2= gcd(k− 1,q− 1). We show that in many situations the necessary conditions λ(q− 1) ≡ 0 mod (k− 1), λq(q− 1) ≡ 0 modk(k− 1), and
λ
≤
(
k
−
2
q
−
2
)
are also sufficient for the existence of a simple (q, k, λ) BIBD. These new results improve the valid range of simple BIBDs.
2010Mathematics Subject Classification. Primary 05B05; Secondary 12E20.
Key words and phrases. Balanced incomplete block design, Finite field, Generating block. |
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ISSN: | 1027-5487 2224-6851 |
DOI: | 10.11650/tjm.20.2016.5021 |