The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A138653 a(n) = 3*a(n-1)-3*a(n-2)+a(n-3)+a(n-4). 1
1, 2, 4, 8, 15, 27, 48, 86, 156, 285, 521, 950, 1728, 3140, 5707, 10379, 18884, 34362, 62520, 113737, 206897, 376362, 684652, 1245504, 2265815, 4121947, 7498552, 13641134, 24815508, 45143621, 82124025, 149397854, 271780616, 494415932, 899427827, 1636214155 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Sequence is identical to its shifted third differences.
LINKS
Denis Neiter and Amsha Proag, Links Between Sums Over Paths in Bernoulli's Triangles and the Fibonacci Numbers, Journal of Integer Sequences, Vol. 19 (2016), Article 16.8.3.
FORMULA
G.f.: (1-x+x^2+x^3) / (1-3*x+3*x^2-x^3-x^4). - Colin Barker, Oct 18 2016
MATHEMATICA
LinearRecurrence[{3, -3, 1, 1}, {1, 2, 4, 8}, 14] (* Ray Chandler, Sep 23 2015 *)
PROG
(PARI) Vec((1-x+x^2+x^3)/(1-3*x+3*x^2-x^3-x^4) + O(x^50)) \\ Colin Barker, Oct 18 2016
CROSSREFS
Sequence in context: A289692 A074029 A248729 * A367223 A284275 A054159
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, May 15 2008
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 21:52 EDT 2024. Contains 372882 sequences. (Running on oeis4.)