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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A099517 A transform of (1-x)/(1-2x). 0
1, 1, 2, 3, 6, 10, 17, 27, 44, 71, 116, 188, 305, 493, 798, 1291, 2090, 3382, 5473, 8855, 14328, 23183, 37512, 60696, 98209, 158905, 257114, 416019, 673134, 1089154, 1762289, 2851443, 4613732, 7465175, 12078908, 19544084, 31622993, 51167077 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

A transform of A011782 under the mapping g(x)->(1/(1+x^3))g(x/(1+x^3))

FORMULA

G.f.: (1-x+x^3)/((1+x^3)(1-2x+x^3)); a(n)=2a(n-1)-2a(n-3)+2a(n-4)-a(n-6); a(n)=sum{k=0..floor(n/3), binomial(n-2k, k)(-1)^k(2^(n-3k)+0^(n-3k))/2}.

CROSSREFS

Cf. A099505, A099508, A099516, A000071.

Sequence in context: A140669 A001636 A036588 * A026647 A026669 A023614

Adjacent sequences:  A099514 A099515 A099516 * A099518 A099519 A099520

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Oct 20 2004

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 13 10:09 EST 2012. Contains 205451 sequences.