Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A057081
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A057081 Even indexed Chebyshev U-polynomials evaluated at sqrt(11)/2. +0
4
1, 10, 89, 791, 7030, 62479, 555281, 4935050, 43860169, 389806471, 3464398070, 30789776159, 273643587361, 2432002510090, 21614379003449, 192097408520951, 1707262297685110, 15173263270645039, 134852107138120241 (list; graph; listen)
OFFSET

0,2

COMMENT

This is the m=11 member of the m-family of sequences S(n,m-2)+S(n-1,m-2) = S(2*n,sqrt(m)) (for S(n,x) see Formula). The m=4..10 instances are: A005408, A002878, A001834, A030221, A002315, A033890, and A057080, resp. The m=1..3 (signed) sequences are: A057078, A057077, and A057079, resp.

a(n) = L(n,-9)*(-1)^n, where L is defined as in A108299; see also A070998 for L(n,+9). - Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Jun 01 2005

REFERENCES

W. Lang, On polynomials related to powers of the generating function of Catalan's numbers, Fib. Quart. 38,5 (2000) 408-419; Eq.(44), rhs, m=11.

LINKS

Tanya Khovanova, Recursive Sequences

Index entries for sequences related to Chebyshev polynomials.

FORMULA

a(n) = 9*a(n-1)-a(n-2), a(-1)=-1, a(0)=1.

a(n)= S(n, 9)+S(n-1, 9)= S(2*n, sqrt(11)) with S(n, x) := U(n, x/2), Chebyshev polynomials of 2nd kind, A049310. S(n, 9)= A018913(n).

G.f.: (1+x)/(1-9*x+x^2).

Let q(n, x)=sum(i=0, n, x^(n-i)*binomial(2*n-i, i)); then (-1)^n*q(n, -11)=a(n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Nov 10 2002

CROSSREFS

Sequence in context: A000826 A031416 A120923 this_sequence A024132 A044261 A065690

Adjacent sequences: A057078 A057079 A057080 this_sequence A057082 A057083 A057084

KEYWORD

nonn

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de) Aug 04 2000

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified July 4 18:25 EDT 2008. Contains 140886 sequences.


AT&T Labs Research