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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A155040 A symmetric (1,-1)-triangle. 1
 1, 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, 1, -1, 1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Row sums are A007877(n+1). Diagonal sums are A155041. LINKS FORMULA Number triangle T(n,k)=sum{j=0..n, [j<=k]*[j<=n-k]*(-1)*(((-1)^(j+1)-0^(j+1))-((-1)^j-0^j))}. EXAMPLE Triangle begins .1, .1, 1, .1, -1, 1, .1, -1, -1, 1, .1, -1, 1, -1, 1, .1, -1, 1, 1, -1, 1, .1, -1, 1, -1, 1, -1, 1, .1, -1, 1, -1, -1, 1, -1, 1, .1, -1, 1, -1, 1, -1, 1, -1, 1, .1, -1, 1, -1, 1, 1, -1, 1, -1, 1, .1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, .1, -1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1 CROSSREFS Sequence in context: A246016 A306638 A076479 * A209661 A033999 A000012 Adjacent sequences:  A155037 A155038 A155039 * A155041 A155042 A155043 KEYWORD easy,sign,tabl AUTHOR Paul Barry, Jan 19 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.

Last modified April 20 23:46 EDT 2021. Contains 343143 sequences. (Running on oeis4.)