The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors 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

%I #18 Sep 08 2022 08:45:28

%S 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,

%T 465,378,127,1,21,147,525,1085,1323,889,255,1,24,196,840,2170,3528,

%U 3556,2040,511,1,27,252,1260,3906,7938,10668,9180,4599,1023

%N Triangle read by rows: T(n,k) = (2^k-1)*binomial(n-1,k-1) (1<=k<=n).

%C Row sums give A027649.

%H G. C. Greubel, <a href="/A124929/b124929.txt">Table of n, a(n) for the first 50 rows, flattened</a>

%e First few rows of the triangle are:

%e 1;

%e 1, 3;

%e 1, 6, 7;

%e 1, 9, 21, 15;

%e 1, 12, 42, 60, 31;

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

%e ...

%p 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

%t Table[(2^k -1)*Binomial[n-1, k-1], {n,12}, {k,n}]//Flatten (* _G. C. Greubel_, Jun 08 2017 *)

%o (PARI) for(n=1,12, for(k=1,n, print1((2^k -1)*binomial(n-1,k-1), ", "))) \\ _G. C. Greubel_, Jun 08 2017

%o (Magma) [(2^k -1)*Binomial(n-1,k-1): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Nov 19 2019

%o (Sage) [[(2^k -1)*binomial(n-1,k-1) for k in (1..n)] for n in (1..12)] # _G. C. Greubel_, Nov 19 2019

%o (GAP) Flat(List([1..12], n-> List([1..n], k-> (2^k -1)*Binomial(n-1,k-1) ))); # _G. C. Greubel_, Nov 19 2019

%Y Cf. A027649.

%K nonn,tabl

%O 1,3

%A _Gary W. Adamson_, Nov 12 2006

%E Edited by _N. J. A. Sloane_, Nov 29 2006

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 14 14:46 EDT 2024. Contains 372533 sequences. (Running on oeis4.)