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1, 6, 24, 82, 261, 804, 2440, 7356, 22113, 66394, 199248, 597822, 1793557, 5380776, 16142448, 48427480, 145282593, 435847950, 1307544040, 3922632330, 11767897221, 35303691916, 105911076024, 317733228372, 953199685441
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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REFERENCES
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A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 189, 194-196.
P. Ribenhoim, The Little Book of Big Primes, Springer-Verlag, N.Y., 1991, p. 53.
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LINKS
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FORMULA
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a(n) = ((3^(n+3)) - (2*(n^2) + 12n + 19))/8.
a(n) = 3a(n-1)+C(n+2,2); a(0)=1.
a(n) = sum{k=0..n, binomial(n+3, k+3)2^k}. - Paul Barry, Aug 20 2004
a(n) = 6*a(n-1) - 12*a(n-2) + 10*a(n-3) - 3*a(n-4).
G.f.: 1/((x-1)^3*(3*x-1)). (End)
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MATHEMATICA
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LinearRecurrence[{6, -12, 10, -3}, {1, 6, 24, 82}, 40] (* Harvey P. Dale, Sep 05 2013 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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