|
Search: id:A117441
|
|
|
| A117441 |
|
Periodic with period {1,1,0,1,-1,0,-1,-1,0,-1,1,0}. |
|
+0
2
|
|
| 1, 1, 0, 1, -1, 0, -1, -1, 0, -1, 1, 0, 1, 1, 0, 1, -1, 0, -1, -1, 0, -1, 1, 0, 1, 1, 0, 1, -1, 0, -1, -1, 0, -1, 1, 0
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
Diagonal sums of number triangle A117440.
|
|
FORMULA
|
G.f.: (1+x-x^2)/(1-x^2+x^4); a(n)=sum{k=0..floor(n/2), C(n-k,k)*(cos(pi*(n-2k)/2)+sin(pi*(n-2k)/2)}.
a(n)=(1/12)*{-(n mod 12)+[(n+1) mod 12]-2*[(n+2) mod 12]+[(n+3) mod 12]-[(n+4) mod 12]+[(n+6) mod 12]-[(n+7) mod 12]+2*[(n+8) mod 12]-[(n+9) mod 12]+[(n+10) mod 12]}, with n>=0 - Paolo P. Lava (ppl(AT)spl.at), Jun 11 2007
|
|
CROSSREFS
|
Sequence in context: A016118 A011646 A016350 this_sequence A049347 A010892 A091338
Adjacent sequences: A117438 A117439 A117440 this_sequence A117442 A117443 A117444
|
|
KEYWORD
|
easy,sign,more
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), Mar 16 2006
|
|
|
Search completed in 0.002 seconds
|
