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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103327 Triangle T(n, k) read by rows: binomial(2n+1, 2k+1). 7
1, 3, 1, 5, 10, 1, 7, 35, 21, 1, 9, 84, 126, 36, 1, 11, 165, 462, 330, 55, 1, 13, 286, 1287, 1716, 715, 78, 1, 15, 455, 3003, 6435, 5005, 1365, 105, 1, 17, 680, 6188, 19448, 24310, 12376, 2380, 136, 1, 19, 969, 11628, 50388, 92378, 75582, 27132, 3876, 171 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

A subset of Pascal's triangle A007318.

Elements have the same parity as those of Pascal's triangle.

Matrix inverse is A104033. - Paul D. Hanna (pauldhanna(AT)juno.com), Feb 28 2005

REFERENCES

A. T. Benjamin and J. J. Quinn, Proofs that really count: the art of combinatorial proof, M.A.A. 2003, id. 224.

FORMULA

G.f. for column k is sum{k=0..k+1, C(2(k+1), 2j)x^j)/(1-x)^(2(k+1)) - Paul Barry (pbarry(AT)wit.ie), Feb 24 2005

G.f.: A(x, y) = (1 + x*(1-y))/( (1 + x*(1-y))^2 - 4*x ). - Paul D. Hanna (pauldhanna(AT)juno.com), Feb 28 2005

Sum_{k, 0<=k<=n} T(n, k)*A000364(n-k) = A002084(n) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Aug 27 2005

EXAMPLE

1

3,1

5,10,1

7,35,21,1

9,84,126,36,1

11,165,462,330,55,1

13,286,1287,1716,715,78,1

15,455,3003,6435,5005,1365,105,1

PROG

(PARI) {T(n, k)=local(X=x+x*O(x^n), Y=y+y*O(y^k)); polcoeff(polcoeff((1+X*(1-Y))/((1+X*(1-Y))^2-4*X), n, x), k, y)} (Hanna)

(Maxima) create_list(binomial(2*n+1, 2*k+1), n, 0, 12, k, 0, n); [Emanuele Munarini, Mar 11 2011]

CROSSREFS

Reflected version of A091042. Cf. A086645, A103328.

Cf. A104033.

Sequence in context: A146916 A146255 A122366 * A177463 A065229 A093905

Adjacent sequences:  A103324 A103325 A103326 * A103328 A103329 A103330

KEYWORD

nonn,tabl

AUTHOR

Ralf Stephan, Feb 06 2005

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 17 21:13 EST 2012. Contains 206085 sequences.