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!)
A174677 a(n) = 2*a(n-1)*a(n-2) with a(0)=1 and a(1)=1. 3
1, 1, 2, 4, 16, 128, 4096, 1048576, 8589934592, 18014398509481984, 309485009821345068724781056, 11150372599265311570767859136324180752990208 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
a(n) = 2^(Fibonacci(n+1)-1).
a(n) = 1/2 * A000301(n+1).
a(n) is the number of node minimal AVL trees of height n. - Alois P. Heinz, Mar 13 2013
LINKS
MATHEMATICA
Join[{a=1, b=2}, Table[c=2*a*b; a=b; b=c, {n, 12}]] (* Vladimir Joseph Stephan Orlovsky, Apr 19 2011 *)
RecurrenceTable[{a[1]==1, a[2]==2, a[n]==2a[n-1]a[n-2]}, a[n], {n, 12}] (* Harvey P. Dale, Jul 07 2011 *)
PROG
(Magma) [(2^(Fibonacci(n+1)-1): n in [1..10]]; // Vincenzo Librandi, Apr 24 2011
CROSSREFS
Sequence in context: A144526 A179532 A217994 * A073924 A362065 A061588
KEYWORD
easy,nonn
AUTHOR
Giovanni Teofilatto, Mar 26 2010
EXTENSIONS
Formula index corrected by R. J. Mathar, Mar 30 2010
a(0)=1 prepended and name edited by Alois P. Heinz, Jul 05 2021
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 March 28 12:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)