Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A127767
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A127767 Inverse of number triangle A(n,k)=if(k<=n,if(n<=2k,1/C(n),0),0), C(n)=A000108(n). +0
2
1, 0, 1, 0, -1, 2, 0, 1, -2, 5, 0, 0, 0, -5, 14, 0, -1, 2, 0, -14, 42, 0, 0, 0, 0, 0, -42, 132, 0, 1, -2, 5, 0, 0, -132, 429, 0, 0, 0, 0, 0, 0, 0, -429, 1430, 0, 0, 0, -5, 14, 0, 0, 0, -1430, 4862, 0, 0, 0, 0, 0, 0, 0, 0, 0, -4862, 16796 (list; table; graph; listen)
OFFSET

0,6

COMMENT

It is conjectured that all elements of the triangle are integers. Row sums give A127768.

EXAMPLE

Triangle begins

1,

0, 1,

0, -1, 2,

0, 1, -2, 5,

0, 0, 0, -5, 14,

0, -1, 2, 0, -14, 42,

0, 0, 0, 0, 0, -42, 132,

0, 1, -2, 5, 0, 0, -132, 429,

0, 0, 0, 0, 0, 0, 0, -429, 1430,

0, 0, 0, -5, 14, 0, 0, 0, -1430, 4862,

0, 0, 0, 0, 0, 0, 0, 0, 0, -4862, 16796

Inverse of triangle

1,

0, 1,

0, 1/2, 1/2,

0, 0, 1/5, 1/5,

0, 0, 1/14, 1/14, 1/14,

0, 0, 0, 1/42, 1/42, 1/42,

0, 0, 0, 1/132, 1/132, 1/132, 1/132,

0, 0, 0, 0, 1/429, 1/429, 1/429, 1/429,

0, 0, 0, 0, 1/1430, 1/1430, 1/1430, 1/1430, 1/1430,

0, 0, 0, 0, 0, 1/4862, 1/4862, 1/4862, 1/4862, 1/4862,

0, 0, 0, 0, 0, 1/16796, 1/16796, 1/16796, 1/16796, 1/16796, 1/16796

CROSSREFS

Sequence in context: A071502 A074704 A025247 this_sequence A055509 A006667 A112570

Adjacent sequences: A127764 A127765 A127766 this_sequence A127768 A127769 A127770

KEYWORD

sign,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jan 28 2007

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


AT&T Labs Research