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A054485
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Expansion of (1+3x)/(1-4x+x^2).
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3
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1, 7, 27, 101, 377, 1407, 5251, 19597, 73137, 272951, 1018667, 3801717, 14188201, 52951087, 197616147, 737513501, 2752437857, 10272237927, 38336513851, 143073817477, 533958756057
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| I. Adler, Three Diophantine equations - Part II, Fib. Quart., 7 (1969), pps. 181-193.
A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pps. 122-125, 194-196.
E. I. Emerson, Recurrent Sequences in the Equation DQ^2=R^2+N, Fib. Quart., 7 (1969), pps. 231-242.
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LINKS
| Tanya Khovanova, Recursive Sequences
Index to sequences with linear recurrences with constant coefficients, signature (4,-1).
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FORMULA
| a(n)=4a(n-1)-a(n-2), a(0)=1, a(0)=7.
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EXAMPLE
| a(n)={7*([2+sqrt(3)]^n-[2-sqrt(3)]^n)-([2+sqrt(3)]^(n-1)-[2-sqrt(3)]^(n-1))}/2*sqrt(3).
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CROSSREFS
| Cf. A054491.
Sequence in context: A059769 A135914 A006350 * A090856 A055917 A056120
Adjacent sequences: A054482 A054483 A054484 * A054486 A054487 A054488
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KEYWORD
| easy,nonn
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AUTHOR
| Barry E. Williams, May 06 2000
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