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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A124929 Triangle read by rows: T(n,k) = (2^k-1)*binomial(n-1,k-1) (1<=k<=n). 4
1, 1, 3, 1, 6, 7, 1, 9, 21, 15, 1, 12, 42, 60, 31, 1, 15, 70, 150, 155, 63, 1, 18, 105, 300, 465, 378, 127, 1, 21, 147, 525, 1085, 1323, 889, 255, 1, 24, 196, 840, 2170, 3528, 3556, 2040, 511, 1, 27, 252, 1260, 3906, 7938, 10668, 9180, 4599, 1023, 1, 30, 315, 1800 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row sums = 2*(3^n) - 2^n = A027649: (1, 4, 14, 46, 146...).

LINKS

G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

EXAMPLE

First few rows of the triangle are:

1;

1, 3;

1, 6, 7;

1, 9, 21, 15;

1, 12, 42, 60, 31;

1, 15, 70, 150, 155, 63;

...

MAPLE

T:=(n, k)->(2^k-1)*binomial(n-1, k-1): for n from 1 to 11 do seq(T(n, k), k=1..n) od; # yields sequence in triangular form

MATHEMATICA

T[n_, k_] := (2^k - 1)*Binomial[n - 1, k - 1]; Table[T[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* G. C. Greubel, Jun 08 2017 *)

PROG

(PARI) for(n=1, 10, for(k=1, n, print1((2^k -1)*binomial(n-1, k-1), ", "))) \\ G. C. Greubel, Jun 08 2017

CROSSREFS

Cf. A027649.

Sequence in context: A291217 A198614 A239385 * A208766 A259454 A209696

Adjacent sequences:  A124926 A124927 A124928 * A124930 A124931 A124932

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Nov 12 2006

EXTENSIONS

Edited by N. J. A. Sloane, Nov 29 2006

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 October 18 22:31 EDT 2018. Contains 316327 sequences. (Running on oeis4.)