The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A015531 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A015531

Linear 2nd order recurrence: a(n) = 4*a(n-1) + 5*a(n-2).
(history; published version)

#83 by Alois P. Heinz at Sun Aug 04 19:10:04 EDT 2024

STATUS

reviewed

approved

#82 by Andrew Howroyd at Sun Aug 04 18:43:13 EDT 2024

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proposed

reviewed

#81 by Jason Yuen at Sun Aug 04 18:34:52 EDT 2024

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editing

proposed

#80 by Jason Yuen at Sun Aug 04 18:34:39 EDT 2024

FORMULA

a(n) = ((2+sqrt(9))^n - (2-sqrt(9))^n)/6. - Al Hakanson (hawkuu(AT)gmail.com), Jan 07 2009]

STATUS

approved

editing

#79 by Charles R Greathouse IV at Thu Sep 08 08:44:40 EDT 2022

PROG

(MAGMAMagma) [Round(5^n/6): n in [0..30]]; // Vincenzo Librandi, Jun 24 2011

Discussion

Thu Sep 08

08:44

OEIS Server: https://oeis.org/edit/global/2944

#78 by Joerg Arndt at Sun Mar 13 01:57:44 EST 2022

STATUS

editing

approved

#77 by Joerg Arndt at Sun Mar 13 01:57:39 EST 2022

FORMULA

E.g.f.(exp(5*x)-exp(-x))/6. (End) (corrected by M. F. Hasler, Jan 29 2012)

MATHEMATICA

k=0; lst={k}; Do[k=5^n-k; AppendTo[lst, k], {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 11 2008 *)

PROG

(PARI) a(n)=5^n\/6 ; \\ Charles R Greathouse IV, Apr 14 2014

STATUS

approved

editing

#76 by Alois P. Heinz at Mon Jan 27 21:43:16 EST 2020

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proposed

approved

#75 by Michael De Vlieger at Mon Jan 27 16:32:48 EST 2020

STATUS

editing

proposed

#74 by Michael De Vlieger at Mon Jan 27 16:32:46 EST 2020

LINKS

Jean-Paul Allouche, Jeffrey Shallit, Zhixiong Wen, Wen Wu, Jiemeng Zhang, <a href="https://arxiv.org/abs/1911.01687">Sum-free sets generated by the period-k-folding sequences and some Sturmian sequences</a>, arXiv:1911.01687 [math.CO], 2019.

STATUS

approved

editing