login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A036830 Schoenheim bound L_1(n,n-4,n-5). 3
3, 7, 14, 26, 44, 70, 105, 152, 213, 291, 388, 508, 654, 829, 1037, 1281, 1566, 1896, 2276, 2710, 3203, 3761, 4388, 5091, 5875, 6746, 7710, 8774, 9944, 11228, 12632, 14164, 15831, 17641, 19602, 21722, 24009, 26472, 29120, 31961, 35005 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,1

REFERENCES

W. H. Mills and R. C. Mullin, Coverings and packings, pp. 371-399 of J. H. Dinitz and D. R. Stinson, editors,a Contemporary Design Theory, Wiley, 1992. See Eq. 1.

LINKS

Table of n, a(n) for n=6..46.

Index entries for covering numbers

FORMULA

a(6)=3 a(n)=ceiling(n/(n-4)*a(n-1)) - Benoit Cloitre, May 31 2003

MAPLE

A036830 := proc(n) local i, t1; t1 := 1; for i from 6 to n do t1 := ceil(t1*i/(i-4)); od: t1; end;

L := proc(v, k, t, l) local i, t1; t1 := l; for i from v-t+1 to v do t1 := ceil(t1*i/(i-(v-k))); od: t1; end; # gives Schoenheim bound L_l(v, k, t)

PROG

(PARI) a(n)=if(n<7, 3, ceil(n/(n-4)*a(n-1)))

CROSSREFS

Lower bound to A066225.

A column of A036838.

Sequence in context: A206417 A207381 A008646 * A014153 A001924 A079921

Adjacent sequences:  A036827 A036828 A036829 * A036831 A036832 A036833

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 11 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 21 04:59 EDT 2019. Contains 321364 sequences. (Running on oeis4.)