A079219 -id:A079219 - cp's OEIS frontend

A090313 a(n) = 22*a(n-1) + a(n-2), starting with a(0) = 2 and a(1) = 22.

2, 22, 486, 10714, 236194, 5206982, 114789798, 2530582538, 55787605634, 1229857906486, 27112661548326, 597708411969658, 13176697724880802, 290485058359347302, 6403847981630521446, 141175140654230819114

Offset: 0

Nikolay V. Kosinov (kosinov(AT)unitron.com.ua), Jan 25 2004

Lim_{n-> infinity} a(n)/a(n+1) = 0.045361... = 1/(11+sqrt(122)) = (sqrt(122)-11).

Lim_{n-> infinity} a(n+1)/a(n) = 22.045361... = (11+sqrt(122)) = 1/(sqrt(122)-11).

			a(4) = 236194 = 22*a(3) + a(2) = 22*10714 + 486 = (11 + sqrt(122))^4 + (11 - sqrt(122))^4 = 236193.999995766 + 0.000004233 = 236194.

G. C. Greubel, Table of n, a(n) for n = 0..500
Tanya Khovanova, Recursive Sequences
Index entries for recurrences a(n) = k*a(n - 1) +/- a(n - 2)
Index entries for linear recurrences with constant coefficients, signature (22,1).

Cf. A079219.

Lucas polynomials Lucas(n,m): A000032 (m=1), A002203 (m=2), A006497 (m=3), A014448 (m=4), A087130 (m=5), A085447 (m=6), A086902 (m=7), A086594 (m=8), A087798 (m=9), A086927 (m=10), A001946 (m=11), A086928 (m=12), A088316 (m=13), A090300 (m=14), A090301 (m=15), A090305 (m=16), A090306 (m=17), A090307 (m=18), A090308 (m=19), A090309 (m=20), A090310 (m=21), this sequence (m=22), A090314 (m=23), A090316 (m=24), A330767 (m=25).

m:=22;; a:=[2,m];; for n in [3..20] do a[n]:=m*a[n-1]+a[n-2]; od; a; # G. C. Greubel, Dec 30 2019

m:=22; I:=[2,m]; [n le 2 select I[n] else m*Self(n-1) +Self(n-2): n in [1..20]]; // G. C. Greubel, Dec 30 2019

seq(simplify(2*(-I)^n*ChebyshevT(n, 11*I)), n = 0..20); # G. C. Greubel, Dec 30 2019

LucasL[Range[20]-1,22] (* G. C. Greubel, Dec 29 2019 *)

vector(21, n, 2*(-I)^(n-1)*polchebyshev(n-1, 1, 11*I) ) \\ G. C. Greubel, Dec 30 2019

[2*(-I)^n*chebyshev_T(n, 11*I) for n in (0..20)] # G. C. Greubel, Dec 30 2019

a(n) = 22*a(n-1) + a(n-2), starting with a(0) = 2 and a(1) = 22.
a(n) = (11+sqrt(122))^n + (11-sqrt(122))^n.
(a(n))^2 = a(2n) - 2 if n=1, 3, 5...,
(a(n))^2 = a(2n) + 2 if n=2, 4, 6....
G.f.: (2-22*x)/(1-22*x-x^2). - Philippe Deléham, Nov 02 2008
a(n) = Lucas(n, 22) = 2*(-i)^n * ChebyshevT(n, 11*i). - G. C. Greubel, Dec 30 2019

More terms from Ray Chandler, Feb 14 2004

A079217 Triangle T(n,d) (listed row-wise: T(1,1)=1, T(2,1)=1, T(2,2)=1, T(3,1)=2, T(3,2)=0, T(3,3)=1, ...) giving the number of n-edge general plane trees with root degree d that are fixed by Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

Original entry on oeis.org

1, 1, 1, 2, 0, 1, 3, 1, 0, 1, 5, 0, 0, 0, 1, 6, 2, 1, 0, 0, 1, 10, 0, 0, 0, 0, 0, 1, 11, 5, 0, 1, 0, 0, 0, 1, 18, 0, 2, 0, 0, 0, 0, 0, 1, 21, 11, 0, 0, 1, 0, 0, 0, 0, 1, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 35, 26, 3, 2, 0, 1, 0, 0, 0, 0, 0, 1, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 69, 66, 0, 0, 0, 0, 1, 0, 0

Offset: 0

Antti Karttunen Jan 03 2002

Index entries for sequences related to parenthesizing

The row sums equal to the left edge shifted left once = A057546 = first row of A079216 (the latter gives the Maple procedure PFixedByA057511).

Cf. A079218, A079219, A079220, A079221, A079222 and A003056 and A002262.

[seq(A079217(n),n=0..119)]; A079217 := n -> PFixedByA057511(A003056(n)+1,1, A002262(n)+1);

A079222 Triangle T(n,d) (listed row-wise: T(1,1)=1, T(2,1)=1, T(2,2)=1, T(3,1)=2, T(3,2)=2, T(3,3)=1, ...) giving the number of n-edge general plane trees with root degree d that are fixed by the six-fold application of Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 5, 5, 3, 1, 14, 14, 9, 0, 1, 38, 42, 28, 2, 0, 1, 111, 124, 90, 0, 0, 6, 1, 332, 379, 285, 5, 0, 27, 0, 1, 1029, 1178, 914, 0, 0, 110, 0, 0, 1, 3232, 3742, 2955, 14, 1, 429, 0, 0, 0, 1, 10374, 12024, 9666, 0, 0, 1614, 0, 0, 0, 0, 1, 33679, 39200, 31853, 42, 0

Offset: 0

Antti Karttunen Jan 03 2002

Note: the counts given here are inclusive, i.e. T(n,d) includes also the counts A079218(n,d) and A079219(n,d).

The row sums equal to the left edge shifted left once = A079227 = sixth row of A079216 (the latter gives the Maple procedure PFixedByA057511). Cf. also A079217-A079221 and A003056 & A002262.

[seq(A079222(n),n=0..119)]; A079222 := n -> PFixedByA057511(A003056(n)+1,6, A002262(n)+1);

A079224 Number of Catalan objects fixed by three-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

Original entry on oeis.org

1, 1, 2, 3, 8, 18, 43, 104, 273, 702, 1870, 4985, 13562, 37038, 102266, 283774, 793189, 2227115, 6286044, 17811751, 50672898, 144639235, 414181050, 1189365940, 3424477813, 9883578364, 28589660227, 82870288432, 240672107114

Offset: 0

Antti Karttunen Jan 03 2002

nonn

The third row of A079216. The leftmost edge of the triangle A079219 and also its row sums shifted by one. Occurs in A073202 as row 43639. Cf. A057546, A079223-A079227.

Maple
```
A079224 := n -> A079216bi(n,3);
```

a(n) = A079216(n, 3)

cp's OEIS Frontend

A090313 a(n) = 22*a(n-1) + a(n-2), starting with a(0) = 2 and a(1) = 22.

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A079217 Triangle T(n,d) (listed row-wise: T(1,1)=1, T(2,1)=1, T(2,2)=1, T(3,1)=2, T(3,2)=0, T(3,3)=1, ...) giving the number of n-edge general plane trees with root degree d that are fixed by Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

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Maple

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Maple

A079224 Number of Catalan objects fixed by three-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

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