A011977 Covering numbers C(n,5,2).

1, 3, 3, 4, 5, 6, 7, 9, 10, 12, 13, 15, 16, 18, 19, 21, 21, 27, 28, 30, 30, 37, 38, 40

Offset

5,2

Comments

It is known that 42 <= a(29) <= 43. The next few values are known: a(30) = 48, a(31) = 50, a(32) = 52. - Nathaniel Johnston, Jan 10 2024

References

CRC Handbook of Combinatorial Designs, 1996, p. 262.

Links

Table of n, a(n) for n=5..28.

D. Gordon, La Jolla Repository of Coverings

Uenal Mutlu (uenalm(AT)metronet.de), Tables of coverings.

Wikipedia, Covering design.

Index entries for covering numbers

Crossrefs

Cf. A011975, A240116.

Sequence in context: A279400 A063197 A327226 * A104803 A104804 A240207

Adjacent sequences: A011974 A011975 A011976 * A011978 A011979 A011980

Keyword

nonn,hard,more

Author

N. J. A. Sloane

Extensions

a(28) from Nathaniel Johnston, Jan 10 2024

Status

approved