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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103219 Triangle read by rows: T(n,k) = (n+1-k)*(4*(n+1-k)^2 - 1)/3+2*k*(n+1-k)^2. 2
1, 10, 3, 35, 18, 5, 84, 53, 26, 7, 165, 116, 71, 34, 9, 286, 215, 148, 89, 42, 11, 455, 358, 265, 180, 107, 50, 13, 680, 553, 430, 315, 212, 125, 58, 15, 969, 808, 651, 502, 365, 244, 143, 66, 17, 1330, 1131, 936, 749, 574, 415, 276, 161, 74, 19, 1771, 1530, 1293 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The triangle is generated from the product B * A of the infinite lower triangular matrices A =

1 0 0 0...

3 1 0 0...

5 3 1 0...

7 5 3 1...

...

and B =

1 0 0 0...

1 3 0 0...

1 3 5 0...

1 3 5 7...

...

LINKS

Table of n, a(n) for n=0..57.

EXAMPLE

Triangle begins:

1,

10,3,

35,18,5,

84,53,26,7,

165,116,71,34,9,

286,215,148,89,42,11,

MATHEMATICA

T[n_, k_] := (n + 1 - k)*(4*(n + 1 - k)^2 - 1)/3 + 2*k*(n + 1 - k)^2; Flatten[ Table[ T[n, k], {n, 0, 10}, {k, 0, n}]] (* Robert G. Wilson v, Feb 10 2005 *)

PROG

(PARI) T(n, k)=(n+1-k)*(4*(n+1-k)^2-1)/3+2*k*(n+1-k)^2; for(i=0, 10, for(j=0, i, print1(T(i, j), ", ")); print())

CROSSREFS

Row sums give A103220.

T(n, 0 = n*(4*n^2 - 1)/3 = A000447(n+1);

T(n+1, n)= 8*n+2 = A017089(n+1);

Cf. A103218 (for product A*B), A103220.

Sequence in context: A243239 A079670 A050100 * A260680 A111126 A165790

Adjacent sequences:  A103216 A103217 A103218 * A103220 A103221 A103222

KEYWORD

nonn,tabl

AUTHOR

Lambert Klasen (lambert.klasen(AT)gmx.de) and Gary W. Adamson, Jan 26 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 January 21 11:09 EST 2020. Contains 331105 sequences. (Running on oeis4.)