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Search: id:A060870
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| A060870 |
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Number of n X n matrices over GF(5) with rank 1. |
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+0
2
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| 4, 144, 3844, 97344, 2439844, 61027344, 1525839844, 38146777344, 953673339844, 23841853027344, 596046423339844, 14901161071777344, 372529029235839844, 9313225743103027344, 232830643638610839844, 5820766091270446777344
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,200
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FORMULA
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a(n) = 1/4 * (5^n - 1)^2
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EXAMPLE
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a(2) = 144 because there are 145 (the second element in sequence A060720) singular 2X2 matrices over GF(5), that have rank <= 1 of which only the zero matrix has rank zero so a(2) = 145 - 1 = 144.
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PROGRAM
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(PARI) { for (n=1, 200, write("b060870.txt", n, " ", (5^n - 1)^2 / 4); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 13 2009]
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CROSSREFS
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A060720.
Sequence in context: A017294 A134631 A036511 this_sequence A084703 A122747 A069135
Adjacent sequences: A060867 A060868 A060869 this_sequence A060871 A060872 A060873
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KEYWORD
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nonn,easy
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AUTHOR
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Ahmed Fares (ahmedfares(AT)my-deja.com), May 04 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001
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