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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A041061 Denominators of continued fraction convergents to sqrt(37). 6
1, 12, 145, 1752, 21169, 255780, 3090529, 37342128, 451196065, 5451694908, 65871534961, 795910114440, 9616792908241, 116197425013332, 1403985893068225, 16964028141832032, 204972323595052609, 2476631911282463340, 29924555258984612689, 361571295019097815608 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Sqrt(37) = 6.08276253... = 12/2 + 12/145 + 12/(145*21169) + 12/(21169*3090529) + ... - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jun 13 2008

For positive n, a(n) equals the permanent of the nXn tridiagonal matrix with 12's along the main diagonal and 1's along the superdiagonal and the subdiagonal. [From John M. Campbell, Jul 08 2011]

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 0..500

Tanya Khovanova, Recursive Sequences

FORMULA

a(n)=F(n, 12), the n-th Fibonacci polynomial evaluated at x=12. - T. D. Noe (noe(AT)sspectra.com), Jan 19 2006

a(n)=12*a(n-1)+a(n-2), n>1 ; a(0)=1, a(1)=12. G.f.: 1/(1-12*x-x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 21 2008]

a(n)=((6+sqrt(37))^(n+1)-(6-sqrt(37))^(n+1))/(2*sqrt(37)). [From Rolf Pleisch (r_pleisch(AT)gmx.ch), May 14 2011]

MATHEMATICA

a=0; lst={}; s=0; Do[a=s-(a-1); AppendTo[lst, a]; s+=a*12, {n, 3*4!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 27 2009]

PROG

(Other) sage: [lucas_number1(n, 12, -1) for n in xrange(1, 18)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 28 2009]

CROSSREFS

Cf. A041060.

Sequence in context: A067219 A075619 A055332 * A174227 A041266 A015501

Adjacent sequences:  A041058 A041059 A041060 * A041062 A041063 A041064

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 23:45 EST 2012. Contains 205978 sequences.