login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A005826 Worst case of a Jacobi symbol algorithm.
(Formerly M3961)
2
1, 5, 31, 141, 659, 3005, 13739, 62669, 285931, 1304285, 5949691, 27139821, 123799979, 564720125, 2576001179, 11750565389, 53600825611, 244502996765, 1115313334651, 5087560678701, 23207176728299, 105860762282045 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=0..21.

Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992.

Simon Plouffe, 1031 Generating Functions and Conjectures, Université du Québec à Montréal, 1992.

J. Shallit, On the worst case of three algorithms for computing the Jacobi symbol, J. Symbolic Comput. 10 (1990), no. 6, 593-610, Variable S_n conjecture 6.2.

Index entries for linear recurrences with constant coefficients, signature (5, 0, -10, 4).

FORMULA

a(n) = 5*a(n-1) - 10a(n-3) + 4a(n-4) by definition [R. J. Mathar, Mar 11 2009]

MAPLE

A005826:=(-1-6*z**2+4*z**3)/(2*z**2-1)/(1-5*z+2*z**2); [Conjectured (correctly) by Simon Plouffe in his 1992 dissertation.]

CROSSREFS

Sequence in context: A184446 A077719 A235462 * A293716 A294692 A047109

Adjacent sequences:  A005823 A005824 A005825 * A005827 A005828 A005829

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jeffrey Shallit

EXTENSIONS

More terms from L. Edson Jeffery, Dec 07 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 15 01:20 EST 2018. Contains 318141 sequences. (Running on oeis4.)