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a(n) = ceiling(binomial(n,8)/n).
4

%I #10 Sep 08 2022 08:45:00

%S 0,0,0,0,0,0,0,1,1,5,15,42,99,215,429,805,1430,2431,3978,6299,9690,

%T 14535,21318,30645,43263,60088,82225,111004,148005,195098,254475,

%U 328697,420732,534006,672452,840565,1043460,1286934,1577532,1922618

%N a(n) = ceiling(binomial(n,8)/n).

%H G. C. Greubel, <a href="/A053731/b053731.txt">Table of n, a(n) for n = 1..1000</a>

%H R. L. Graham and N. J. A. Sloane, <a href="http://dx.doi.org/10.1109/TIT.1980.1056141">Lower bounds for constant weight codes</a>, IEEE Trans. Inform. Theory, 26 (1980), 37-43.

%p seq(ceil(binomial(n,8)/n), n=1..45); # _G. C. Greubel_, Sep 06 2019

%t Table[Ceiling[Binomial[n, 8]/n], {n, 45}] (* _G. C. Greubel_, Sep 06 2019 *)

%o (PARI) vector(45, n, ceil(binomial(n,8)/n)) \\ _G. C. Greubel_, Sep 06 2019

%o (Magma) [Ceiling(Binomial(n,8)/n): n in [1..45]]; // _G. C. Greubel_, Sep 06 2019

%o (Sage) [ceil(binomial(n,8)/n) for n in (1..45)] # _G. C. Greubel_, Sep 06 2019

%Y Cf. Sequences of the form ceiling(binomial(n,k)/n): A000012 (k=1), A004526 (k=2), A007997 (k=3), A008646 (k=5), A032192 (k=7), A053618 (k=4), A053643 (k=6), this sequence (k=8), A053733 (k=9).

%K nonn

%O 1,10

%A _N. J. A. Sloane_, Mar 25 2000