login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A112227 A scaled Hermite triangle. 0
1, 0, 1, -2, 0, 1, 0, -6, 0, 1, 12, 0, -12, 0, 1, 0, 60, 0, -20, 0, 1, -120, 0, 180, 0, -30, 0, 1, 0, -840, 0, 420, 0, -42, 0, 1, 1680, 0, -3360, 0, 840, 0, -56, 0, 1, 0, 15120, 0, -10080, 0, 1512, 0, -72, 0, 1, -30240, 0, 75600, 0, -25200, 0, 2520, 0, -90, 0, 1, 0, -332640, 0, 277200, 0, -55440, 0, 3960, 0, -110, 0, 1, 665280, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Inverse of number triangle A067147. Diagonal sums are A002119.

LINKS

Table of n, a(n) for n=0..79.

Index entries for sequences related to Hermite polynomials

FORMULA

Number triangle T(n, k)=A060821(n, k)/2^k; T(n, k)=n!/(k!*2^((n-k)/2)((n-k)/2)!)*cos(pi*(n-k)/2)*2^((n+k)/2)(1+(-1)^(n+k))/2^(k+1) T(n, k)=A001498((n+k)/2, (n-k)/2)*cos(pi(n-k)/2)*2^((n+k)/2)(1+(-1)^(n+k))/2^(k+1);

Exponential Riordan array (e^(-x^2),x). - Paul Barry, Sep 12 2006

EXAMPLE

Triangle begins

1;

0,1;

-2,0,1;

0,-6,0,1;

12,0,-12,0,1;

0,60,0,-20,0,1;

MATHEMATICA

(* The function RiordanArray is defined in A256893. *)

rows = 12;

R = RiordanArray[E^(-#^2)&, #&, rows, True];

R // Flatten

CROSSREFS

Sequence in context: A265089 A166357 A067147 * A166378 A249820 A136579

Adjacent sequences:  A112224 A112225 A112226 * A112228 A112229 A112230

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Aug 28 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 17 12:55 EDT 2021. Contains 343971 sequences. (Running on oeis4.)