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Search: id:A072465
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| A072465 |
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A Fibonacci-like model in which each pair of rabbits dies after the birth of their 4-th litter: a(n) = a(n-2) + a(n-3) + a(n-4) + a(n-5). |
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1
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| 1, 1, 1, 2, 3, 5, 7, 11, 17, 26, 40, 61, 94, 144, 221, 339, 520, 798, 1224, 1878, 2881, 4420, 6781, 10403, 15960, 24485, 37564, 57629, 88412, 135638, 208090, 319243, 489769, 751383, 1152740, 1768485, 2713135, 4162377, 6385743, 9796737
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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lim n ->infinity a(n+1)/a(n) = 1.534157744914.... is the root of x^5 = x^3+x^2+x+1 - Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 22 2002
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REFERENCES
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Gridgeman, N. T.; Fibonacci Quart., vol. 11 (1973), no. 1, 40-55
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FORMULA
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a(n) = a(n-1) + a(n-2) - a(n-6); g.f.: = (1 + x)/(1 - x^2 - x^3 - x^4 - x^5).
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MATHEMATICA
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CoefficientList[ Series[(1 + x)/(1 - x^2 - x^3 - x^4 - x^5), {x, 0, 40}], x]
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CROSSREFS
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Sequence in context: A055500 A018058 A002379 this_sequence A052284 A133670 A127272
Adjacent sequences: A072462 A072463 A072464 this_sequence A072466 A072467 A072468
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KEYWORD
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easy,nonn
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AUTHOR
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Leonardo Fonseca (fonleo(AT)fisica.ufmg.br), Jun 19 2002
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