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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A166555 Triangle read by rows, Sierpinski's gasket, A047999 * (1,2,4,8,...) diagonalized. 2
1, 1, 2, 1, 0, 4, 1, 2, 4, 8, 1, 0, 0, 0, 16, 1, 2, 0, 0, 16, 32, 1, 0, 4, 0, 16, 0, 64, 1, 2, 4, 8, 16, 32, 64, 128, 1, 0, 0, 0, 0, 0, 0, 0, 256, 1, 2, 0, 0, 0, 0, 0, 0, 256, 512, 1, 0, 4, 0, 0, 0, 0, 0, 256, 0, 1024 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Row sums = A001317: (1, 3, 5, 15, 17, 51, 85,...).

Number of positive terms in n-th row (n>=0) equals to A000120(n). [From Vladimir Shevelev, Oct 25 2010]

LINKS

Table of n, a(n) for n=0..65.

FORMULA

Triangle read by rows, A047999 * Q. A047999 = Sierpinski's gasket, Q = an infinite lower triangular matrix with (1,2,4,8,...) as the main diagonal and the rest zeros.

EXAMPLE

First few rows of the triangle =

1;

1, 2;

1, 0, 4;

1, 2, 4, 8;

1, 0, 0, 0, 16;

1, 2, 0, 0, 16,.32;

1, 0, 4, 0, 16,..0,..64;

1, 2, 4, 8, 16,.32,..64,..128;

1, 0, 0, 0,..0,..0,...0,....0,..256;

1, 2, 0, 0,..0,..0,...0,....0,..256,...512;

1, 0, 4, 0,..0,..0,...0,....0,..256,.....0,...1024;

1, 2, 4, 8,..0,..0,...0,....0,..256,...512,...l024,...2048;

1, 0, 0, 0, 16,..0,...0,....0,..256,.....0,......0,......0,..4096;

...

CROSSREFS

Cf. A147999, A001317.

Sequence in context: A143724 A143425 A323376 * A136329 A122073 A106236

Adjacent sequences:  A166552 A166553 A166554 * A166556 A166557 A166558

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Oct 17 2009

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 August 8 14:36 EDT 2020. Contains 336298 sequences. (Running on oeis4.)