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A137213
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First differences of A137212.
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1
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0, 1, 4, 15, 52, 173, 560, 1779, 5576, 17305, 53308, 163287, 497980, 1513541, 4587944, 13878075, 41910032, 126395953, 380795380, 1146267039, 3448170436, 10367130845, 31156000928, 93599839107, 281117798360, 844121793481
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OFFSET
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0,3
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LINKS
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FORMULA
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O.g.f.: 1/(1-3*x) - 1/(1-2*x-x^2) = x*(1-x)/( (1-3*x)*(1-2*x-x^2) ).
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MATHEMATICA
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LinearRecurrence[{5, -5, -3}, {0, 1, 4}, 30] (* Harvey P. Dale, Apr 18 2019 *)
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PROG
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(Magma) [n le 3 select (n-1)^2 else 5*Self(n-1) -5*Self(n-2) -3*Self(n-3): n in [1..31]]; // G. C. Greubel, Jan 05 2022
(Sage) [3^n - lucas_number1(n+1, 2, -1) for n in (0..30)] # G. C. Greubel, Jan 05 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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