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A082365
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A Jacobsthal number sequence.
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8
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1, 11, 85, 683, 5461, 43691, 349525, 2796203, 22369621, 178956971, 1431655765, 11453246123, 91625968981, 733007751851, 5864062014805, 46912496118443, 375299968947541, 3002399751580331, 24019198012642645, 192153584101141163
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| A trisection of A024495. - Paul Curtz, Nov 18 2007
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
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FORMULA
| a(n) = 4*8^n/3-(-1)^n/3.
a(n) = J(3*n+2) = A001045(3*n)/3.
a(0)=1, a(1)=11, a(n+1)=7*a(n)+8*a(n-1) for n>=1 . G.f.: (1+4x)/(1-7x-8x^2) . - Philippe DELEHAM, Nov 19 2007
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MATHEMATICA
| f[n_] := (4*8^n - (-1)^n)/3; Array[f, 20, 0] (* Robert G. Wilson v, Aug 13 2011 *)
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PROG
| (MAGMA) [4*8^n/3-(-1)^n/3: n in [0..30]]; // Vincenzo Librandi, Aug 13 2011
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CROSSREFS
| Cf. A015565, A082311.
Sequence in context: A026783 A001240 A129180 * A012794 A014917 A080962
Adjacent sequences: A082362 A082363 A082364 * A082366 A082367 A082368
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Apr 09 2003
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