Presentation 2023-12-22
The ultimate signs of second-order holonomic sequences
Akitoshi Kawamura, Fugen Hagihara,
PDF Download Page PDF download Page Link
Abstract(in Japanese) (See Japanese page)
Abstract(in English) A real-valued sequence ${f(n)} _{n in mathbb{N}}$ is said to be second-order holonomic if it satisfies a linear recurrence $P _2 (n) f (n + 2) = P _1 (n) f (n + 1) + P _0 (n) f (n)$, where $P _0$, $P _1$, $P _2$ are polynomials and $P _2 neq 0$.We study the ultimate signs of such a sequence, i.e., the repeated pattern that the signs of $f (n)$ follow for sufficiently large $n$.We classify all possible ultimate signs in terms of the degrees and the first few coefficients of $P _0$, $P _1$ and $P _2$, completing prior work by Neumann, Ouaknine, and Worrell who have settled some restricted cases.As a corollary, it follows that when $P_0$, $P_1$, $P_2$ have rational coefficients, $f$ either has an ultimate sign of length $1$, $2$, $3$, $4$, $6$, $8$ or $12$, or never falls into a repeated sign pattern.We also give an algorithm that, given $P_0$, $P_1$, $P_2$, the initial values and some additional information of them, outputs when $f$ reaches the ultimate state.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) holonomic / P-finite / linear recurrence / ultimate sign / decidability
Paper # COMP2023-25
Date of Issue 2023-12-15 (COMP)

Conference Information
Committee COMP
Conference Date 2023/12/22(1days)
Place (in Japanese) (See Japanese page)
Place (in English) Miyazaki Univ. Machinaka Campus
Topics (in Japanese) (See Japanese page)
Topics (in English) Theoretical Computer Science, etc
Chair Hiroyuki Uno(Osaka Metropolitan Univ.)
Vice Chair Shuji Kijima(Shiga Univ.)
Secretary Shuji Kijima(Hosei Univ.)
Assistant Ei Ando(Senshu Univ.)

Paper Information
Registration To Technical Committee on Theoretical Foundations of Computing
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) The ultimate signs of second-order holonomic sequences
Sub Title (in English)
Keyword(1) holonomic
Keyword(2) P-finite
Keyword(3) linear recurrence
Keyword(4) ultimate sign
Keyword(5) decidability
1st Author's Name Akitoshi Kawamura
1st Author's Affiliation Kyoto University(Kyoto Univ.)
2nd Author's Name Fugen Hagihara
2nd Author's Affiliation Kyoto University(Kyoto Univ.)
Date 2023-12-22
Paper # COMP2023-25
Volume (vol) vol.123
Number (no) COMP-325
Page pp.pp.56-60(COMP),
#Pages 5
Date of Issue 2023-12-15 (COMP)