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.

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A078108 Let u(1)=u(2)=1, u(3)=2n, u(k) = abs(u(k-1)-u(k-2)-u(k-3)) and M(k) = Max_{i<=i<=k} u(i), then for any k >= A078109(n), M(k) = floor(sqrt(k + a(n))).

Original entry on oeis.org

4, 24, 156, 184, 324, 608, 940, 1784, 1844, 3104, 5996, 4600, 4484, 6128, 6220, 7208, 8244, 9424, 11740, 13560, 14836, 19264, 19756, 23344, 24524, 26224, 32940, 34912, 34548, 42808, 52428, 46120, 47492, 52280, 67908, 86120, 80084, 147152
Offset: 1

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Author

Benoit Cloitre, Dec 05 2002

Keywords

Comments

It appears that (1) a(n) always exists, (2) a(n) is even, (3) a(n)/n^(5/2) -> infinity. If initial conditions are u(1)=u(2)=1, u(3)=2n+1, then u(k) reaches a 2-cycle for any k>m large enough (cf. A078098). - Benoit Cloitre, Jan 29 2006

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Extensions

Typos in data corrected by Sean A. Irvine, Jun 16 2025

A078109 Let u(1)=u(2)=1, u(3)=2n, u(k) = abs(u(k-1)-u(k-2)-u(k-3)) and M(k) = Max_{1<=i<=k} u(i), then for any k >= a(n), M(k) = floor(sqrt(k + A078108(n))).

Original entry on oeis.org

3, 10, 38, 10, 35, 66, 19, 150, 90, 30, 243, 159, 138, 270, 19, 186, 35, 178, 358, 127, 46, 334, 123, 370, 438, 343, 182, 430, 46, 454, 470, 534, 30, 618, 734, 903, 570, 302, 571, 638, 30, 166, 822, 647, 426, 998, 75, 106, 606, 322, 82, 210, 1798, 330, 506
Offset: 1

Views

Author

Benoit Cloitre, Dec 05 2002

Keywords

Comments

Conjecture : a(n) always exists, a(n)/n^2 is bounded. If initial conditions are u(1)=u(2)=1, u(3)=2n+1, then u(k) reaches a 2-cycle for any k>m large enough (cf. A078098)

Crossrefs

Extensions

Typos in data corrected and more terms from Sean A. Irvine, Jun 16 2025
Showing 1-2 of 2 results.