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Search: id:A058481
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| 1, 7, 25, 79, 241, 727, 2185, 6559, 19681, 59047, 177145, 531439, 1594321, 4782967, 14348905, 43046719, 129140161, 387420487, 1162261465, 3486784399, 10460353201, 31381059607, 94143178825, 282429536479, 847288609441
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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2 X n binary matrices with no zero rows or columns.
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FORMULA
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Number of m X n binary matrices with no zero rows or columns is Sum_{j=0..m}(-1)^j*C(m, j)*(2^(m-j)-1)^n.
G.f.: 1/(1-3*x)-2/(1-x). E.g.f.: e^(3*x)-2*(e^x). [From Mohammad K. Azarian (azarian(AT)evansville.edu), Jan 14 2009]
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MATHEMATICA
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a=1; lst={a}; Do[a=a*3+4; AppendTo[lst, a], {n, 0, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 25 2008]
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CROSSREFS
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Cf. A055602, A024206 (unlabeled case), A055609, A058482, A000244.
Cf. A003462, A007051, A034472, A024023, A067771, A029858, A134931, A115099, A100774, A079004 [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 25 2008]
Sequence in context: A155281 A155254 A155295 this_sequence A155294 A155233 A146933
Adjacent sequences: A058478 A058479 A058480 this_sequence A058482 A058483 A058484
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KEYWORD
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easy,nonn,nice
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AUTHOR
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Vladeta Jovovic (vladeta(AT)eunet.rs), Nov 26 2000
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Dec 04 2000
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