A121488 a(n) = 8*n^2 - floor(n*sqrt(8))^2.

4, 7, 8, 7, 4, 32, 31, 28, 23, 16, 7, 63, 56, 47, 36, 23, 8, 92, 79, 64, 47, 28, 7, 119, 100, 79, 56, 31, 4, 144, 119, 92, 63, 32, 196, 167, 136, 103, 68, 31, 223, 188, 151, 112, 71, 28, 248, 207, 164, 119, 72, 23, 271, 224, 175, 124, 71, 16, 292, 239, 184, 127, 68, 7

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

a(n) = 8*n^2 - floor(n*sqrt(8))^2.

Example

a(2) = 8*2^2-floor(2*sqrt(8))^2 = 32-25 = 7.

Maple

A121488:=n->8*n^2-floor(n*sqrt(8))^2: seq(A121488(n), n=1..100); # Wesley Ivan Hurt, Feb 15 2017

Mathematica

Table[8n^2-Floor[n*Sqrt[8]]^2, {n, 64}] (* James C. McMahon, Oct 19 2024 *)

Prog

(PARI) a(n) = 8*n^2 - sqrtint(8*n^2)^2 \\ Charles R Greathouse IV, Feb 15 2017

Crossrefs

Sequence in context: A272490 A261654 A332504 * A115291 A108615 A310937

Adjacent sequences: A121485 A121486 A121487 * A121489 A121490 A121491

Keyword

nonn,easy

Author

Clark Kimberling, Aug 02 2006

Status

approved