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A109995 Number of unlabeled ordered minimal T_0-covers of an n-set, cf. A094545. 1
1, 1, 1, 2, 5, 18, 86, 549, 4647, 52060, 772976, 15240116, 400345371, 14063594530, 663256392496, 42161077371566, 3625838175218123, 423372648479289300, 67333725775723184308, 14628921614102655999804, 4352732830667872529962044 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
FORMULA
a(n) = Sum_{m=0..n} binomial(2^m-m-1, n-m).
MATHEMATICA
Table[Sum[Binomial[2^m-m-1, n-m], {m, 0, n}], {n, 0, 50}] (* _G. C. Greubel_, Oct 08 2017 *)
PROG
(PARI) for(n=0, 50, print1(sum(m=0, n, binomial(2^m -m -1, n-m)), ", ")) \\ _G. C. Greubel_, Oct 08 2017 *)
CROSSREFS
Sequence in context: A371800 A020029 A020119 * A142153 A287227 A094294
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda, _Vladeta Jovovic_, Sep 01 2005
STATUS
approved

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Last modified May 23 15:34 EDT 2024. Contains 372763 sequences. (Running on oeis4.)