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!)
A178934 a(n) = floor((3*4^n + 2*3^n)/5). 2
1, 3, 13, 49, 186, 711, 2749, 10705, 41946, 165159, 652765, 2587441, 10278906, 40903047, 162974461, 649984657, 2594199066, 10359577575, 41386654237, 165391648753, 661101690426, 2643012047943, 10567864050493, 42258903778129 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..23.

FORMULA

a(n) = 7*a(n-1) - 12*a(n-2) + a(n-4) - 7*a(n-5) + 12*a(n-6); initial terms are 1, 3, 13, 49, 186, 711.

a(n) = 6*a(n-1) - 6*a(n-2) - 6*a(n-3) - 5*a(n-4) - 12*a(n-5) - 6; initial terms are 1, 3, 13, 49, 186.

G.f.: (1-4*x+4*x^2-6*x^3-2*x^4+x^5)/((1-3*x)*(1-4*x)*(1-x^4)).

PROG

(Maxima) makelist(floor((3*4^n+2*3^n)/5), n, 0, 12);

(MAGMA) [ (3*4^n+2*3^n) div 5: n in [0..30] ]; // Vincenzo Librandi, Dec 31 2010

(PARI) a(n) = (3*4^n + 2*3^n)\5 \\ Michel Marcus, Apr 24 2018

CROSSREFS

Cf. A178935, A178936.

Sequence in context: A048482 A094978 A251743 * A218420 A241775 A045908

Adjacent sequences:  A178931 A178932 A178933 * A178935 A178936 A178937

KEYWORD

nonn,easy

AUTHOR

Emanuele Munarini, Dec 30 2010

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 January 25 02:32 EST 2021. Contains 340414 sequences. (Running on oeis4.)