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.

A373095 a(n) = a[n/4] + a[n/8] + a[n/16] + ..., where a(0) = 0, a(1) = 1, and [ ] = floor.

Original entry on oeis.org

0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
Offset: 0

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Author

Clark Kimberling, May 28 2024

Keywords

Comments

Every term is a Fibonacci number (A000045), and every nonnegative Fibonacci number occurs.

Examples

			a(20) = a(5) + a(2) + a(1) = 1 + 0 + 1 = 2.
		

Crossrefs

Cf. A000045, A005187, A072376 (sum starts with a[n/2]), A373096, A373097.

Programs

  • Mathematica
    a[0] = 0; a[1] = 1;
    a[n_] := a[n] = Sum[a[Floor[n/2^k]], {k, 2, n}]
    Table[a[n], {n, 0, 570}]

Formula

The initial 16 terms (0s and 1s) are followed by 16 twos, then 32 threes, then 64 fives,... . Specifically, for m>=3, there are 2^(m+1) F(m)'s.