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2, 26, 242, 2186, 19682, 177146, 1594322, 14348906, 129140162, 1162261466, 10460353202, 94143178826, 847288609442, 7625597484986, 68630377364882, 617673396283946, 5559060566555522, 50031545098999706, 450283905890997362
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,1
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LINKS
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FORMULA
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a(n) = 9*a(n-1)+8, n>0.
a(n) = 10*a(n-1)-9*a(n-2), n>1.
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MATHEMATICA
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CoefficientList[Series[2*(1 + 3*x)/(1 - 10*x + 9*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)
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PROG
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(Magma) [3*9^n-1: n in [0..20]]
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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