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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108045 Triangle read by rows: lower triangular matrix obtained by inverting the lower triangular matrix in A108044. 3
1, 0, 1, -2, 0, 1, 0, -3, 0, 1, 2, 0, -4, 0, 1, 0, 5, 0, -5, 0, 1, -2, 0, 9, 0, -6, 0, 1, 0, -7, 0, 14, 0, -7, 0, 1, 2, 0, -16, 0, 20, 0, -8, 0, 1, 0, 9, 0, -30, 0, 27, 0, -9, 0, 1, -2, 0, 25, 0, -50, 0, 35, 0, -10, 0, 1, 0, -11, 0, 55, 0, -77, 0, 44, 0, -11, 0, 1, 2, 0, -36, 0, 105, 0, -112, 0, 54, 0, -12, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

This triangle describes the Chebyshev transform of A100047 and following. Chebyshev transform of sequence b is c(n) = SUM (a(n,k)*b(k), k=1 to n). - Christian G. Bower, Jun 12 2005

REFERENCES

Aoife Hennessy, A Study of Riordan Arrays with Applications to Continued Fractions, Orthogonal Polynomials and Lattice Paths, Ph. D. Thesis, Waterford Institute of Technology, Oct. 2011; http://repository.wit.ie/1693/1/AoifeThesis.pdf

L. W. Shapiro, S. Getu, W.-J. Woan and L. C. Woodson, The Riordan group, Discrete Applied Math., 34 (1991), 229-239.

LINKS

Table of n, a(n) for n=0..90.

FORMULA

Riordan array ( (1-x^2)/(1+x^2), x/(1+x^2)).

G.f.=(1-x^2)/(1+x^2-tx). - Emeric Deutsch, Jun 06 2005

EXAMPLE

Triangle begins:

.1

.0 1

.-2 0 1

.0 -3 0 1

.2 0 -4 0 1

MAPLE

f:=(1-x^2)/(1+x^2): g:=x/(1+x^2): G:=simplify(f/(1-t*g)): Gser:=simplify(series(G, x=0, 14)): P[0]:=1: for n from 1 to 12 do P[n]:=coeff(Gser, x^n) od: for n from 0 to 12 do seq(coeff(t*P[n], t^k), k=1..n+1) od; # yields sequence in triangular form (Deutsch)

CROSSREFS

Cf. A007318, A108044.

Cf. A127672.

Sequence in context: A053119 A162515 A175267 * A143728 A127368 A112552

Adjacent sequences:  A108042 A108043 A108044 * A108046 A108047 A108048

KEYWORD

sign,tabl,easy

AUTHOR

N. J. A. Sloane, Jun 02 2005

EXTENSIONS

More terms from Emeric Deutsch and Christian G. Bower, Jun 06 2005

STATUS

approved

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 June 19 10:21 EDT 2013. Contains 226401 sequences.