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Search: id:A117917
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| A117917 |
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a(n) = 3*a(n-1) + a(n-2) + n. |
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+0
1
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| 1, 4, 15, 52, 175, 582, 1927, 6370, 21045, 69514, 229597, 758316, 2504557, 8272000, 27320571, 90233728, 298021771, 984299058, 3250918963, 10737055966, 35462086881, 117123316630, 386832036793, 1277619427032, 4219690317913
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Simple recursive sequence.
a(n)/a(n-1) tends to 3.30277563... = expArcSinh(3/2).
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FORMULA
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O.g.f.: -(1-x+x^2)/{(-1+x)^2 (-1+3*x+x^2)} . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 17 2008
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EXAMPLE
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a(5) = 582 = 3*a(n-1) + a(n-2) + n; = 3*175 + 52 + 5.
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CROSSREFS
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Adjacent sequences: A117914 A117915 A117916 this_sequence A117918 A117919 A117920
Sequence in context: A137213 A027853 A132894 this_sequence A027295 A057332 A071719
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KEYWORD
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nonn
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AUTHOR
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Gary W. Adamson (qntmpkt(AT)yahoo.com), Apr 02 2006
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 17 2008
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