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)binom(n-1,k-1) (1<=k<=n). 2
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; internal format)
OFFSET

1,3

COMMENTS

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

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, 127;

...

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

CROSSREFS

Cf. A027649.

Sequence in context: A089511 A112692 A198614 * A199662 A103407 A074475

Adjacent sequences:  A124926 A124927 A124928 * A124930 A124931 A124932

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Nov 12 2006

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Nov 29 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 13 16:17 EST 2012. Contains 205522 sequences.