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Search: id:A070333
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| A070333 |
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Expansion of (1+x^3)/(1-3*x+3*x^2-2*x^3+3*x^4-3*x^5+x^6). |
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+0
1
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| 1, 3, 6, 12, 21, 33, 50, 72, 99, 133, 174, 222, 279, 345, 420, 506, 603, 711, 832, 966, 1113, 1275, 1452, 1644, 1853, 2079, 2322, 2584, 2865, 3165, 3486, 3828, 4191, 4577, 4986, 5418, 5875, 6357, 6864, 7398, 7959, 8547, 9164, 9810, 10485
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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a(n) is the number of 3 X 3 matrices with nonnegative integer entries such that every row sum, column sum and the trace of the matrix is n. - Sharon Sela (sharonsela(AT)hotmail.com), May 20 2002
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MATHEMATICA
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CoefficientList[ Series[(1 + x^3)/(1 - 3*x + 3*x^2 - 2*x^3 + 3*x^4 - 3*x^5 + x^6), {x, 0, 45}], x]
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CROSSREFS
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Cf. A059827, A001844, A002817.
Sequence in context: A034738 A054064 A053479 this_sequence A011779 A161809 A084439
Adjacent sequences: A070330 A070331 A070332 this_sequence A070334 A070335 A070336
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), May 11 2002
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