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A154879
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Third differences of the Jacobsthal sequence A001045.
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12
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3, -2, 4, 0, 8, 8, 24, 40, 88, 168, 344, 680, 1368, 2728, 5464, 10920, 21848, 43688, 87384, 174760, 349528, 699048, 1398104, 2796200, 5592408, 11184808, 22369624, 44739240, 89478488, 178956968, 357913944, 715827880, 1431655768, 2863311528, 5726623064
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OFFSET
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0,1
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COMMENTS
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Second differences of A078008. First differences of the sequence (-1)^(n+1)*A084247(n).
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LINKS
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FORMULA
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a(n) = a(n-1) + 2*a(n-2).
G.f.: (3-5*x)/((1+x)*(1-2*x)). (End)
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MATHEMATICA
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Differences[LinearRecurrence[{1, 2}, {0, 1}, 40], 3] (* or *) LinearRecurrence[ {1, 2}, {3, -2}, 40] (* Harvey P. Dale, Apr 20 2018 *)
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PROG
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CROSSREFS
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KEYWORD
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sign,easy,changed
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AUTHOR
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EXTENSIONS
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Typo in A-number in formula corrected by R. J. Mathar, Feb 23 2009
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STATUS
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approved
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