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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A208481 Diagonal sums of triangle A185384. 2
1, 2, 6, 19, 60, 188, 589, 1846, 5786, 18135, 56840, 178152, 558377, 1750106, 5485310, 17192459, 53885860, 168892996, 529356757, 1659148590, 5200224626, 16298923631, 51085276240, 160115201936, 501844754065, 1572918462066, 4929955864374, 15451827549123 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,0,1,1).

FORMULA

a(n) = sum(binomial(n-k,k)*F(2n-3k+1), k=0..floor(n/2)), where F(n) are the Fibonacci numbers (A000045).

G.f. (1-x)/(1-3*x-x^3-x^4).

Recurrence: a(n+4) = 3*a(n+3)+a(n+1)+a(n).

MATHEMATICA

Table[Sum[Binomial[n-k, k]Fibonacci[2n-3k+1], {k, 0, Floor[n/2]}], {n, 0, 100}]

PROG

(Maxima) makelist(sum(binomial(n-k, k)*fib(2*n-3*k+1), k, 0, floor(n/2)), n, 0, 27);

CROSSREFS

Cf. A185384.

Sequence in context: A183188 A118364 A294500 * A052544 A204200 A318127

Adjacent sequences:  A208478 A208479 A208480 * A208482 A208483 A208484

KEYWORD

nonn,easy

AUTHOR

Emanuele Munarini, Feb 29 2012

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 21 00:17 EDT 2019. Contains 327252 sequences. (Running on oeis4.)