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0, 4, 14, 40, 110, 304, 854, 2440, 7070, 20704, 61094, 181240, 539630, 1610704, 4815734, 14414440, 43177790, 129402304, 387944774, 1163310040, 3488881550, 10464547504, 31389448214, 94159956040, 282463090910, 847355718304
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history;
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OFFSET
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0,2
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REFERENCES
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G. S. Carr, Formulas and Theorems in Pure Mathematics, New York, Chelsea, 1970. see pp. 83-84.
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LINKS
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Table of n, a(n) for n=0..25.
Index to sequences with linear recurrences with constant coefficients, signature (6, -11, 6).
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FORMULA
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G.f.: x * (4 - 10*x) / ((1 - x) * (1 - 2*x) * (1 - 3*x)).
a(0)=0, a(1)=4, a(2)=14, a(n)=6*a(n-1)-11*a(n-2)+6*a(n-3). - Harvey P. Dale, Sep 06 2012
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EXAMPLE
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4*x + 14*x^2 + 40*x^3 + 110*x^4 + 304*x^5 + 854*x^6 + 2440*x^7 + 7070*x^8 + ...
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MATHEMATICA
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Table[3^n+2*2^n-3, {n, 0, 30}] (* or *) LinearRecurrence[{6, -11, 6}, {0, 4, 14}, 30] (* Harvey P. Dale, Sep 06 2012 *)
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PROG
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(PARI) {a(n) = 3^n + 2 * 2^n - 3}
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CROSSREFS
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Sequence in context: A023003 A001872 A054443 * A202900 A032285 A196451
Adjacent sequences: A072671 A072672 A072673 * A072675 A072676 A072677
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KEYWORD
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nonn,easy
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AUTHOR
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Michael Somos, Jul 01 2002
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STATUS
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approved
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