Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A106181
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A106181 Expansion of c(-x^2)(1+2x-sqrt(1+4x^2))/2, c(x) the g.f. of A000108. +0
3
0, 1, -1, -1, 2, 2, -5, -5, 14, 14, -42, -42, 132, 132, -429, -429, 1430, 1430, -4862, -4862, 16796, 16796, -58786, -58786, 208012, 208012, -742900, -742900, 2674440, 2674440, -9694845, -9694845, 35357670, 35357670, -129644790, -129644790, 477638700, 477638700, -1767263190, -1767263190 (list; graph; listen)
OFFSET

0,5

COMMENT

Second column of number triangle A106180.

FORMULA

a(n)=sin(pi*n/2)(C((n-1)/2)(1-(-1)^n)/2)+sin(pi*(n+1)/2)(C(n/2)(1+(-1)^n)/2)-0^n

CROSSREFS

Cf. A099363.

Sequence in context: A095014 A129996 A099363 this_sequence A098887 A097438 A055879

Adjacent sequences: A106178 A106179 A106180 this_sequence A106182 A106183 A106184

KEYWORD

easy,sign

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Apr 24 2005

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 29 12:46 EST 2009. Contains 167659 sequences.


AT&T Labs Research