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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A128137 A002260 * A128132. 1
1, -1, 4, -1, 1, 9, -1, 1, 5, 16, -1, 1, 5, 11, 25, -1, 1, 5, 11, 19, 36, -1, 1, 5, 11, 19, 29, 49, -1, 1, 5, 11, 19, 29, 41, 64, -1, 1, 5, 11, 19, 29, 41, 55, 81, -1, 1, 5, 11, 19, 29, 41, 55, 71, 100 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,3

COMMENTS

Deleting the right and left borders gives terms of A028387: (1, 5, 11, 29, 29, 41, 55, 71,...). Row sums = A064999: (1, 3, 9, 21, 41,...)

FORMULA

A002260 * A128132 as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle are:

1;

-1, 4;

-1, 1, 9;

-1, 1, 5, 16;

-1, 1, 5, 11, 25;

-1, 1, 5, 11, 19, 36;

-1, 1, 5, 11, 19, 29, 49;

...

CROSSREFS

Cf. A002260, A128132, A028387, A128136, A064999.

Sequence in context: A100754 A174035 A055107 * A136100 A183153 A141905

Adjacent sequences:  A128134 A128135 A128136 * A128138 A128139 A128140

KEYWORD

tabl,sign

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Feb 16 2007

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 17 19:13 EST 2012. Contains 206085 sequences.