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 1-2 of 2 results.

A350678 Partial sums of A185381.

Original entry on oeis.org

0, 1, 3, 6, 14, 35, 69, 158, 302, 679, 1666, 3263, 7444, 18390, 36101, 82469, 157494, 353912, 868141, 1700181, 3878490, 7403068, 16630533, 40788350, 79876519, 182210674, 450124970, 883619407, 2018522577, 3854834480, 8662361456, 21248630481, 41613641555, 94929932728, 234513795173
Offset: 0

Views

Author

Michel Marcus, Jan 11 2022

Keywords

Crossrefs

Programs

  • Mathematica
    f[n_] := Fibonacci[Floor[GoldenRatio * n]]; Accumulate @ Array[f, 35, 0] (* Amiram Eldar, Jan 11 2022 *)
  • PARI
    B(n) = (n+sqrtint(5*n^2))\2; \\ A000201
    f(n) = fibonacci(B(n)); \\ A185381
    a(n) = sum(k=1, n, f(k));
    
  • Python
    from math import isqrt
    from sympy import fibonacci
    def A350678(n): return sum(fibonacci((i+isqrt(5*i**2))//2) for i in range(n+1)) # Chai Wah Wu, Jan 11 2022

Formula

a(n) = Sum_{k=1..n} A185381(k).

A107858 a(n) = b(k), where b(k) = Fibonacci(n-1) and k = floor( n*(1+sqrt(5))/2 ).

Original entry on oeis.org

1, 1, 2, 3, 7, 11, 28, 45, 117, 189, 494, 799, 2091, 3383, 8856, 14329, 37513, 60697, 158906, 257115, 673135, 1089155, 2851444, 4613733, 12078909, 19544085, 51167078, 82790071, 216747219, 350704367, 918155952, 1485607537, 3889371025
Offset: 1

Views

Author

Roger L. Bagula, Jun 12 2005

Keywords

Comments

Limit_{n -> oo} a(n+1)/a(n) does not exist.
Apparently the same as A107857. - Georg Fischer, Nov 02 2018

Crossrefs

Programs

  • Mathematica
    F[1] = 0; F[2] = 1; F[n__] := F[n] = F[n - 1] + F[n - 2]
    Table[F[ Floor[(Sqrt[5] + 1)*n/2]], {n, 1, 50}] (* F[n] are the Fibonacci numbers, A000045, with offset 1 *)

Extensions

Edited by N. J. A. Sloane, May 06 2012
Showing 1-2 of 2 results.