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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A073391 Fourth convolution of A002605(n) (generalized (2,2)-Fibonacci), n >= 0, with itself. 2
1, 10, 70, 400, 2020, 9352, 40600, 167680, 665440, 2555840, 9551936, 34880000, 124853120, 439228160, 1521839360, 5202292736, 17571249920, 58712184320, 194280061440, 637228462080, 2073332481024, 6696470231040 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Muniru A Asiru, Table of n, a(n) for n = 0..500

FORMULA

a(n) = Sum_{k=0..n} b(k)*c(n-k) with b(k) := A002605(k) and c(k) := A073390(k).

a(n) = (2^n)*Sum_{k=0..floor(n/2)} binomial(n-k+4, 4)*binomial(n-k, k)*(1/2)^k.

a(n) = (2*(419 + 326*n + 79*n^2 + 6*n^3)*(n+1)*U(n+1) + (458 + 421*n + 112*n^2 + 9*n^3)*(n+2)*U(n))/(2^5*3^4), with U(n) := A002605(n), n >= 0.

G.f.: 1/(1-2*x*(1+x))^5.

PROG

(GAP) List([0..25], n->2^n*Sum([0..Int(n/2)], k->Binomial(n-k+4, 4)*Binomial(n-k, k)*(1/2)^k)); # Muniru A Asiru, Jun 12 2018

CROSSREFS

Fifth (m=4) column of triangle A073387.

Cf. A002605, A073390.

Sequence in context: A271040 A005567 A174434 * A002802 A101029 A122892

Adjacent sequences:  A073388 A073389 A073390 * A073392 A073393 A073394

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Aug 02 2002

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 June 13 03:46 EDT 2021. Contains 344980 sequences. (Running on oeis4.)