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A059301 Number of filter bases of an n-set. 1
1, 5, 31, 569, 165211, 12885396101, 64563604303081738807, 1361129467683753854111752846879267953905, 521064401567922879406069432539095585345840013599959430520674634220747299433267 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 91, #42.

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,12

FORMULA

Sum (binomial(n, k)*2^(2^k-1), k=0..n-1).

PROG

(PARI) { for (n = 1, 12, a=0; for (k=0, n-1, a+=binomial(n, k)*2^(2^k - 1); ); write("b059301.txt", n, " ", a); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jun 25 2009]

CROSSREFS

Sequence in context: A135744 A020514 A201307 * A088548 A062631 A156027

Adjacent sequences:  A059298 A059299 A059300 * A059302 A059303 A059304

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Jan 26 2001

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Last modified February 16 16:00 EST 2012. Contains 205938 sequences.