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!)
A184635 a(n) = floor(1/{(n+n^4)^(1/4)}), where {} = fractional part. 1
5, 16, 36, 64, 100, 144, 196, 256, 324, 400, 484, 576, 676, 784, 900, 1024, 1156, 1296, 1444, 1600, 1764, 1936, 2116, 2304, 2500, 2704, 2916, 3136, 3364, 3600, 3844, 4096, 4356, 4624, 4900, 5184, 5476, 5776, 6084, 6400, 6724, 7056, 7396, 7744, 8100, 8464 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..46.

Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).

FORMULA

a(n) = floor(1/{(n+n^4)^(1/4)}), where {} = fractional part.

It appears that a(n)=3a(n-1)-3a(n-2)+a(n-3) for n>=5, and that a(n)=4*n^2 for n>=2.

MATHEMATICA

p[n_]:=FractionalPart[(n^4+n)^(1/4)];

q[n_]:=Floor[1/p[n]];

Table[q[n], {n, 1, 80}]

FindLinearRecurrence[Table[q[n], {n, 1, 1000}]]

Join[{5}, LinearRecurrence[{3, -3, 1}, {16, 36, 64}, 45]] (* Ray Chandler, Aug 02 2015 *)

CROSSREFS

Cf. A184536, A144916, A016742.

Sequence in context: A234362 A108966 A321019 * A328506 A072333 A055232

Adjacent sequences:  A184632 A184633 A184634 * A184636 A184637 A184638

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 18 2011

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 February 25 11:54 EST 2020. Contains 332233 sequences. (Running on oeis4.)