cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A293552 a(n) is the least integer k such that k/Fibonacci(n) > 1/4.

Original entry on oeis.org

0, 1, 1, 1, 1, 2, 2, 4, 6, 9, 14, 23, 36, 59, 95, 153, 247, 400, 646, 1046, 1692, 2737, 4428, 7165, 11592, 18757, 30349, 49105, 79453, 128558, 208010, 336568, 544578, 881145, 1425722, 2306867, 3732588, 6039455, 9772043, 15811497, 25583539, 41395036, 66978574
Offset: 0

Views

Author

Clark Kimberling, Oct 14 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = 1/4; f[n_] := Fibonacci[n];
    Table[Floor[r*f[n]], {n, 0, z}];   (* A004697 *)
    Table[Ceiling[r*f[n]], {n, 0, z}]; (* A293552 *)
    Table[Round[r*f[n]], {n, 0, z}];   (* A293553 *)

Formula

G.f.: -((x (-1 + x^2 + x^3 + x^5 + x^6))/((-1 + x) (1 + x) (1 - x + x^2) (-1 + x + x^2) (1 + x + x^2))).
a(n) = a(n-1) + a(n-2) + a(n-6) - a(n-7) - a(n-8) for n >= 9.
a(n) = ceiling(Fibonacci(n)/4).
a(n) = A004697(n) + 1 for n > 0.

A293553 a(n) is the integer k that minimizes |k/Fibonacci(n) - 1/4|.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 2, 3, 5, 8, 14, 22, 36, 58, 94, 152, 247, 399, 646, 1045, 1691, 2736, 4428, 7164, 11592, 18756, 30348, 49104, 79453, 128557, 208010, 336567, 544577, 881144, 1425722, 2306866, 3732588, 6039454, 9772042, 15811496, 25583539, 41395035, 66978574
Offset: 0

Views

Author

Clark Kimberling, Oct 14 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = 1/4; f[n_] := Fibonacci[n];
    Table[Floor[r*f[n]], {n, 0, z}];   (* A004697 *)
    Table[Ceiling[r*f[n]], {n, 0, z}]; (* A293552 *)
    Table[Round[r*f[n]], {n, 0, z}];   (* A293553 *)

Formula

G.f.: x^4/((-1 + x) (1 + x) (1 - x + x^2) (-1 + x + x^2) (1 + x + x^2)).
a(n) = a(n-1) + a(n-2) + a(n-6) - a(n-7) - a(n-8) for n >= 9.
a(n) = floor(1/2 + Fibonacci(n)/4).
a(n) = A004697(n) if (fractional part of Fibonacci(n)/4) < 1/2, otherwise a(n) = A293552(n).
a(n) = A131132(n-4) for n > 3. - Georg Fischer, Oct 22 2018

A179006 Partial sums of floor(Fibonacci(n)/4).

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 3, 6, 11, 19, 32, 54, 90, 148, 242, 394, 640, 1039, 1685, 2730, 4421, 7157, 11584, 18748, 30340, 49096, 79444, 128548, 208000, 336557, 544567, 881134, 1425711, 2306855, 3732576, 6039442, 9772030, 15811484
Offset: 0

Views

Author

Mircea Merca, Jan 03 2011

Keywords

Comments

Partial sums of A004697.

Examples

			a(7) = 0 + 0 + 0 + 0 + 0 + 1 + 2 + 3 = 6.
		

Crossrefs

Cf. A004697.

Programs

  • Maple
    A179006 := proc(n) add( floor(combinat[fibonacci](i)/4),i=0..n) ; end proc:
  • Mathematica
    f[n_] := Floor[ Fibonacci@ n/4]; Accumulate@ Array[f, 38]
    LinearRecurrence[{3,-3,2,-2,2,-1,-1,1},{0,0,0,0,0,1,3,6},40] (* Harvey P. Dale, Jan 28 2020 *)
  • PARI
    a(n)={round(fibonacci(n+2)/4 - n/3 - 3/8)} \\ Andrew Howroyd, May 01 2020

Formula

a(n) = 3*a(n-1) - 3*a(n-2) + 2*a(n-3) - 2*a(n-4) + 2*a(n-5) - a(n-6) - a(n-7) + a(n-8).
a(n) = round(Fibonacci(n+2)/4 - n/3 - 3/8).
a(n) = round(Fibonacci(n+2)/4 - n/3 - 1/4).
a(n) = floor(Fibonacci(n+2)/4 - n/3 - 1/12).
a(n) = ceiling(Fibonacci(n+2)/4 - n/3 - 2/3).
a(n) = a(n-6) + Fibonacci(n-1) - 2, n > 6.
G.f.: -x^5/((x^2+x+1)*(x^2-x+1)*(x^2+x-1)*(x-1)^2).
Showing 1-3 of 3 results.