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3 votes

On four Ramanujan-type "Legendrian" sequences with a 3-term recurrence?

Stupid of me. As O. Gorodetsky mentions, these are classical: $$F_1=(91\zeta(3)-2\pi^3\sqrt{3})/432$$ $$F_2=(28\zeta(3)-\pi^3)/64$$ $$F_3=(117\zeta(3)-2\pi^3\sqrt{3})/243$$ In addition, note that ...
Henri Cohen's user avatar
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1 vote

On Zagier's missing continued fraction with multiple limits?

To complete the 12 cfracs in this post and the 4 in the next, all associated with 16 "sporadic sequences", then 13 of them have closed-forms, 1 has six limits (also with closed-forms but one ...
Tito Piezas III's user avatar
0 votes
Accepted

On the continued fractions using Cooper's sequences $s_7,\, s_{10},\, s_{18}$ and the Zudilin-Cohen sequence

(This answers Question 2.) Thanks to Cohen's 2022 paper, turns out there is a deg-$4$ and one can find polynomials $Q_k(n)$ for general deg-$k$ such that, $$(n+1)^k s_{n+1} = Q_k (n)\, s_n - n^k s_{n-...
Tito Piezas III's user avatar
10 votes
Accepted

On Zagier's missing continued fraction with multiple limits?

Set $Q=(1/2)L(\chi_{-3},2)$ (related to your Gieseking constant) and $P=2\pi^2/81$. The limits are almost certainly (not proved), \begin{align} \lim_{m\to\infty}C_2(6m+0) &= -Q\\ \lim_{m\to\infty}...
Henri Cohen's user avatar
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2 votes

On 12 cfracs: for Catalan's $K$, Gieseking's $\kappa$, and $\pi^2$, $\pi^3$, plus three for $\zeta(3)$ using Zagier's "six sporadic sequences"

Zagier answered your first question in his original paper. See the table in p. 11 here. He gives there evaluations of the continued fractions associated with his sequences A, C, D, E and F (note that ...
Ofir Gorodetsky's user avatar
12 votes
Accepted

On 12 cfracs: for Catalan's $K$, Gieseking's $\kappa$, and $\pi^2$, $\pi^3$, plus three for $\zeta(3)$ using Zagier's "six sporadic sequences"

We have $$C_2(-17,-6,-72)=-(5/8)L(\chi_{-3},2)$$ and $$C_2(10,3,-9)=(1/2)L(\chi_{-3},2)$$ so both are proportional to what you call Gieseking's constant but which is simply the value at 2 of the L ...
Henri Cohen's user avatar
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0 votes

Applications of finite continued fractions

Cornacchia's algorithm for solving the Diophantine equation $x^{2}+dy^{2}=m$. See for details On Cornacchia’s algorithm for solving the diophantine equation $x^{2}+dy^{2}=m$ by F. Morain and J.-L. ...

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