A036830 - OEIS

A036830

Schoenheim bound L_1(n,n-4,n-5).

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

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OFFSET

6,1

REFERENCES

W. H. Mills and R. C. Mullin, Coverings and packings, pp. 371-399 of Jeffrey H. Dinitz and D. R. Stinson, editors, 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.