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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A165903 a(n) = (a(n-1)^2+a(n-2)^2+a(n-1)*a(n-2))/a(n-3) with three initial ones. 6
1, 1, 1, 3, 13, 217, 16693, 21717363, 2175145909081, 283430597537694797281, 3699017428454717709381715649628841, 6290488320295607125006566146327310005599469877825552723 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..17

FORMULA

a(n) ~ 1/6 * c^(((1+sqrt(5))/2)^n), where c = 1.902254978346365075882696720546123493664... . - Vaclav Kotesovec, May 06 2015

a(n) = 6*a(n-1)*a(n-2)-a(n-1)-a(n-2)-a(n-3). - Bruno Langlois, Aug 21 2016

MATHEMATICA

RecurrenceTable[{a[0]==1, a[1]==1, a[2]==1, a[n]==(a[n-1]^2+a[n-2]^2+a[n-1]*a[n-2])/a[n-3]}, a, {n, 0, 10}] (* Vaclav Kotesovec, May 06 2015 *)

PROG

(PARI) a(n)=if(n<3, 1, (a(n-1)^2+a(n-2)^2+a(n-1)*a(n-2))/a(n-3))

CROSSREFS

Cf. A064098, A072882, A165896.

Sequence in context: A112093 A085010 A259988 * A100441 A036680 A111431

Adjacent sequences:  A165900 A165901 A165902 * A165904 A165905 A165906

KEYWORD

nonn

AUTHOR

Jaume Oliver Lafont, Sep 29 2009

EXTENSIONS

"frac" keyword removed by Jaume Oliver Lafont, Oct 13 2009

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 10:09 EDT 2018. Contains 316262 sequences. (Running on oeis4.)