|
Search: id:A041181
|
|
|
| A041181 |
|
Denominators of continued fraction convergents to sqrt(101). |
|
+0
3
|
|
| 1, 20, 401, 8040, 161201, 3232060, 64802401, 1299280080, 26050404001, 522307360100, 10472197606001, 209966259480120, 4209797387208401, 84405914003648140, 1692328077460171201, 33930967463207072160
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Generalized Pell numbers (A000129).Anti-diagonals of A038207. [From M. Dols (markdols99(AT)yahoo.com), Aug 31 2009]
|
|
LINKS
|
Tanya Khovanova, Recursive Sequences
|
|
FORMULA
|
a(n)=F(n, 20), the n-th Fibonacci polynomial evaluated at x=20. - T. D. Noe (noe(AT)sspectra.com), Jan 19 2006
a(n)=20*a(n-1)+a(n-2), n>1 ; a(0)=1, a(1)=20 . G.f.: 1/(1-20*x-x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 21 2008]
a(n)=(5/101)*sqrt(101)*{[10+sqrt(101)]^n-[10-sqrt(101)]^n}+(1/2)*{[10 +sqrt(101)]^n+[10-sqrt(101)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Dec 03 2009]
|
|
MATHEMATICA
|
a=0; lst={}; s=0; Do[a=s-(a-1); AppendTo[lst, a]; s+=a*20, {n, 3*4!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 27 2009]
|
|
CROSSREFS
|
Cf. A041180.
Sequence in context: A006494 A007545 A055476 this_sequence A041762 A068772 A158601
Adjacent sequences: A041178 A041179 A041180 this_sequence A041182 A041183 A041184
|
|
KEYWORD
|
nonn,cofr,easy,less,new
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
Search completed in 0.002 seconds
|
