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.

A324475 k appears t+1 times, where t is the number of trailing zeros in A324474(k).

Original entry on oeis.org

1, 2, 3, 3, 4, 4, 5, 5, 5, 6, 7, 7, 7, 8, 9, 9, 9, 9, 10, 11, 12, 12, 13, 13, 13, 13, 14, 15, 16, 16, 17, 17, 17, 17, 17, 18, 19, 20, 20, 21, 21, 22, 22, 22, 23, 24, 24, 24, 24, 24, 25, 26, 27, 27, 28, 28, 29, 29, 29, 30, 31, 31, 31, 31, 31, 31, 32, 33, 34, 34
Offset: 1

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Author

Nathan Fox and N. J. A. Sloane, Mar 09 2019

Keywords

Comments

Interesting because the recurrence is nested one layer deeper than the recurrences for A046699 and A316628.

Crossrefs

Cf. A324474.
A046699, A316628, A324473, A324477 have similar definitions.

Programs

  • PARI
    See Links section.

Formula

For n>3, a(n) = a(n-a(n-1)) + a(n-1-a(n-2)-a(n-2-a(n-2))) + a(n-2-a(n-3)-a(n-3-a(n-3)) - a(n-3-a(n-3)-a(n-3-a(n-3)))). - Nathan Fox, Mar 09 2019 (This formula assumes that a(0) = 0. - Rémy Sigrist, Mar 14 2021)

Extensions

Data corrected and more terms from Rémy Sigrist, Mar 14 2021