The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A119901 Difference between two consecutive squares enclosing 3^(2n+1). 0
3, 11, 31, 93, 281, 841, 2525, 7575, 22727, 68183, 204551, 613655, 1840965, 5522897, 16568691, 49706071, 149118215, 447354647, 1342063941, 4026191825, 12078575475, 36235726425, 108707179277, 326121537829, 978364613487 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
a(n) = 2*Floor(3^((2n + 1)/2)) + 1.
EXAMPLE
a(2)=31 because 3^(2*2+1)=3^5=243, 15^2<243<16^2 and 16^2-15^2=256-225=31.
MATHEMATICA
f[n_] := 2*Floor[3^((2n + 1)/2)] + 1; Table[f[n], {n, 0, 25}] (* Ray Chandler, Jun 09 2006 *)
CROSSREFS
Sequence in context: A291887 A217323 A263781 * A106934 A146581 A146456
KEYWORD
nonn
AUTHOR
Zak Seidov, May 27 2006
EXTENSIONS
Extended by Ray Chandler, Jun 09 2006
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 May 20 11:05 EDT 2024. Contains 372712 sequences. (Running on oeis4.)