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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137948 Triangle read by rows, A000012 * A136579. 6
1, 2, 1, 3, 2, 2, 4, 3, 4, 6, 5, 4, 6, 12, 24, 6, 5, 8, 18, 48, 120, 7, 6, 10, 24, 72, 240, 720, 8, 7, 12, 30, 96, 360, 1440, 5040, 9, 8, 14, 36, 120, 480, 2160, 10080, 40320, 10, 9, 16, 42, 144, 600, 2880, 15120, 80640, 362880 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums = A014144 starting (1, 3, 7, 17, 51, 205,...).

T(n,k) = A245334(n,k) / A007318(n,k), 0 <= k <= n. - Reinhard Zumkeller, Aug 31 2014

LINKS

Reinhard Zumkeller, Rows n = 0..125 of triangle, flattened

FORMULA

As infinite lower triangular matrices, A000012 * A136579, where A000012 = (1; 1,1; 1,1,1;...) and A136579 = (1; 1,1; 1,1,2; 1,1,2,6; 1,1,2,6,24;...).

EXAMPLE

First few rows of the triangle are:

1;

2, 1;

3, 2, 2;

4, 3, 4, 6;

5, 4, 6, 12, 24;

6, 5, 8, 18, 48, 120;

7, 6, 10, 24, 72, 240, 720;

...

PROG

(Haskell)

a137948 n k = a137948_tabl !! n !! k

a137948_row n = a137948_tabl !! n

a137948_tabl = zipWith (zipWith div) a245334_tabl a007318_tabl

-- Reinhard Zumkeller, Aug 31 2014

CROSSREFS

Cf. A136579, A014144.

Cf. A245334, A007318.

Sequence in context: A132923 A144329 A141157 * A210553 A269456 A208906

Adjacent sequences:  A137945 A137946 A137947 * A137949 A137950 A137951

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Feb 28 2008

EXTENSIONS

Offset changed by Reinhard Zumkeller, Aug 31 2014

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 17 22:32 EST 2018. Contains 299297 sequences. (Running on oeis4.)