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A020739 2n + 6. 1
6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Pisot sequence T(6,8).

Trivial case of a Pisot sequence satisfying a simple linear recurrence. Here, since round((2n+2)^2/(2n)^2) = 2n + round((n+1)/n^2) = 2n for n>2, a(n) is even and a(n) = a(n-1) + 2. - Ralf Stephan, Sep 03 2013

LINKS

Table of n, a(n) for n=0..66.

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (2, -1).

FORMULA

a(n) = 2a(n-1) - a(n-2).

MATHEMATICA

2*Range[0, 70]+6 (* or *) Range[6, 138, 2] (* Harvey P. Dale, Apr 24 2017 *)

CROSSREFS

Subsequence of A005843. See A008776 for definitions of Pisot sequences.

Sequence in context: A065985 A233421 A060652 * A064466 A026286 A187085

Adjacent sequences:  A020736 A020737 A020738 * A020740 A020741 A020742

KEYWORD

nonn,easy

AUTHOR

David W. Wilson

EXTENSIONS

Better name from Ralf Stephan, Sep 03 2013

STATUS

approved

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Last modified June 24 02:34 EDT 2017. Contains 288697 sequences.