Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A102224
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A102224 Column 0 of the matrix square of A102220, which equals the lower triangular matrix: [2*I - A008459]^(-1). +0
1
1, 2, 14, 200, 4814, 174752, 8909168, 606818060, 53211837134, 5838211285616, 783434682568664, 126221710572107900, 24043148814317769584, 5344827109234104188348, 1371307353540074156012828 (list; graph; listen)
OFFSET

0,2

COMMENT

A102221 is column 0 of A102220. Triangle A008459 consists of the squared binomial coefficients.

FORMULA

a(n) = Sum_{k=0..n} C(n, k)^2*A102221(k)*A102221(n-k).

Sum_{n>=0} a(n)*x^n/n!^2 = 1/(2-BesselI(0,2*sqrt(x)))^2. - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jul 17 2006

EXAMPLE

Given A102221 = [1,1,5,55,1077,32951,1451723,87054773,...], then

this sequence results from a type of self-convolution of A10221:

a(2) = 14 = 1^2*1*5 + 2^2*1*1 + 1^2*5*1,

a(3) = 200 = 1^2*1*55 + 3^2*1*5 + 3^2*5*1 + 1^2*55*1.

PROGRAM

(PARI) {a(n)=(matrix(n+1, n+1, i, j, if(i==j, 2, 0)-binomial(i-1, j-1)^2)^-2)[n+1, 1]}

CROSSREFS

Cf. A102220, A102221, A008459.

Sequence in context: A132611 A047796 A090300 this_sequence A123543 A054652 A122647

Adjacent sequences: A102221 A102222 A102223 this_sequence A102225 A102226 A102227

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Dec 31 2004

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 November 30 22:12 EST 2008. Contains 150989 sequences.


AT&T Labs Research