A084222 -id:A084222 - cp's OEIS frontend

A014983 a(n) = (1 - (-3)^n)/4.

0, 1, -2, 7, -20, 61, -182, 547, -1640, 4921, -14762, 44287, -132860, 398581, -1195742, 3587227, -10761680, 32285041, -96855122, 290565367, -871696100, 2615088301, -7845264902, 23535794707, -70607384120, 211822152361, -635466457082, 1906399371247

Offset: 0

Olivier Gérard

q-integers for q=-3.
Let A be the Hessenberg matrix of order n, defined by: A[1,j]=1, A[i,i]:=-3, A[i,i-1]=-1, and A[i,j]=0 otherwise. Then, for n>=1, a(n)=(-1)^n*charpoly(A,0). - Milan Janjic, Jan 27 2010
Pisano period lengths:  1, 2, 1, 4, 4, 2, 3, 8, 1, 4, 10, 4, 6, 6, 4, 16, 16, 2, 9, 4, ... - R. J. Mathar, Aug 10 2012

T. D. Noe, Table of n, a(n) for n = 0..200
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 927
László Németh, The trinomial transform triangle, J. Int. Seqs., Vol. 21 (2018), Article 18.7.3. Also arXiv:1807.07109 [math.NT], 2018.
R. A. Sulanke, Moments of generalized Motzkin paths, J. Integer Sequences, Vol. 3 (2000), #00.1.
Index entries for linear recurrences with constant coefficients, signature (-2,3)

Cf. A077925, A014985, A014986, A014987, A014989, A014990, A014991, A014992, A014993, A014994. - Zerinvary Lajos, Dec 16 2008

[(1-(-3)^n)/4: n in [0..30]]; // G. C. Greubel, May 26 2018

a:=n->sum ((-3)^j, j=0..n): seq(a(n), n=-1..25); # Zerinvary Lajos, Dec 16 2008

nn = 25; CoefficientList[Series[x/((1 - x)*(1 + 3*x)), {x, 0, nn}], x] (* T. D. Noe, Jun 21 2012 *)
Table[(1 - (-3)^n)/4, {n, 0, 27}] (* Michael De Vlieger, Nov 23 2016 *)

PARI
```
a(n)=(1-(-3)^n)/4
```

[gaussian_binomial(n,1,-3) for n in range(0,27)] # Zerinvary Lajos, May 28 2009

a(n) = a(n-1) + (-3)^(n-1).
G.f.: x/((1-x)*(1+3*x)).
a(n) = -(-1)^n*A015518(n).
a(n) = the (1, 2)-th element of M^n, where M = ((1, 1, 1, -2), (1, 1, -2, 1), (1, -2, 1, 1), (-2, 1, 1, 1)). - Simone Severini, Nov 25 2004
a(0)=0, a(1)=1, a(n) = -2*a(n-1) + 3*a(n-2) for n>1. - Philippe Deléham, Sep 19 2009
From Sergei N. Gladkovskii, Apr 29 2012: (Start)
G.f. A(x) = G(0)/4; G(k) = 1 - 1/(3^(2*k) - 3*x*3^(4*k)/(3*x*3^(2*k) + 1/(1 + 1/(3*3^(2*k) - 3^(3)*x*3^(4*k)/(3^2*x*3^(2*k) - 1/G(k+1)))))); (continued fraction, 3rd kind, 6-step).
E.g.f. E(x) = G(0)/4; G(k) = 1 - 1/(9^k - 3*x*81^k/(3*x*9^k + (2*k+1)/(1 + 1/(3*9^k - 27*x*81^k/(9*x*9^k - (2*k+2)/G(k+1)))))); (continued fraction, 3rd kind, 6-step). (End)
a(n) = A084222(n) - 1. - Filip Zaludek, Nov 19 2016
E.g.f.: sinh(x)*cosh(x)*exp(-x). - Ilya Gutkovskiy, Nov 20 2016

A084221 a(n+2) = 4*a(n), with a(0)=1, a(1)=3.

Original entry on oeis.org

1, 3, 4, 12, 16, 48, 64, 192, 256, 768, 1024, 3072, 4096, 12288, 16384, 49152, 65536, 196608, 262144, 786432, 1048576, 3145728, 4194304, 12582912, 16777216, 50331648, 67108864, 201326592, 268435456, 805306368, 1073741824, 3221225472, 4294967296, 12884901888

Offset: 0

Paul Barry, May 21 2003

Binomial transform is A060925. Binomial transform of A084222.
Sequences with similar recurrence rules: A016116 (multiplier 2), A038754 (multiplier 3), A133632 (multiplier 5). See A133632 for general formulas. - Hieronymus Fischer, Sep 19 2007
Equals A133080 * A000079. A122756 is a companion sequence. - Gary W. Adamson, Sep 19 2007

			Binary...............Decimal
1..........................1
11.........................3
100........................4
1100......................12
10000.....................16
110000....................48
1000000...................64
11000000.................192
100000000................256
1100000000...............768
10000000000.............1024
110000000000............3072, etc. - _Philippe Deléham_, Mar 21 2014

Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Hester Graves, The Minimal Euclidean Function on the Gaussian Integers, arXiv:1802.08281 [math.NT], 2018. See Definition 2.3 p.3.
Index entries for linear recurrences with constant coefficients, signature (0,4)

For partial sums see A133628. Partial sums for other multipliers p: A027383(p=2), A087503(p=3), A133629(p=5).
Other related sequences: A132666, A132667, A132668, A132669.
Cf. A000302, A133080, A133087, A164346.

[(5*2^n-(-2)^n)/4: n in [0..40]]; // Vincenzo Librandi, Aug 13 2011

CoefficientList[Series[(-3*x - 1)/(4*x^2 - 1), {x, 0, 200}], x] (* Vladimir Joseph Stephan Orlovsky, Jun 10 2011 *)

a(n)=([0,1; 4,0]^n*[1;3])[1,1] \\ Charles R Greathouse IV, Oct 03 2016

a(n) = (5*2^n-(-2)^n)/4.
G.f.: (1+3*x)/((1-2*x)(1+2*x)).
E.g.f.: (5*exp(2*x) - exp(-2*x))/4.
a(n) = A133628(n) - A133628(n-1) for n>1. - Hieronymus Fischer, Sep 19 2007
Equals A133080 * [1, 2, 4, 8, ...]. Row sums of triangle A133087. - Gary W. Adamson, Sep 08 2007
a(n+1)-2a(n) = A000079 signed. a(n)+a(n+2)=5*a(n). First differences give A135520. - Paul Curtz, Apr 22 2008
a(n) = A074323(n+1)*A016116(n). - R. J. Mathar, Jul 08 2009
a(n+3) = a(n+2)*a(n+1)/a(n). - Reinhard Zumkeller, Mar 04 2011
a(n) = Sum_{k=0..n+1} A181650(n+1,k)*2^k. - Philippe Deléham, Nov 19 2011
a(2*n) = A000302(n); a(2*n+1) = A164346(n). - Philippe Deléham, Mar 21 2014

Edited by N. J. A. Sloane, Dec 14 2007

A211866 (9^n - 5) / 4.

Original entry on oeis.org

1, 19, 181, 1639, 14761, 132859, 1195741, 10761679, 96855121, 871696099, 7845264901, 70607384119, 635466457081, 5719198113739, 51472783023661, 463255047212959, 4169295424916641, 37523658824249779, 337712929418248021, 3039416364764232199, 27354747282878089801

Offset: 1

Reinhard Zumkeller, Feb 12 2013

(2*n, a(n)) are the solutions of Diophantine equation 3^x = 4*y + 5.
Second bisection of A080926. - Bruno Berselli, Feb 12 2013
Sum of n-th row of triangle of powers of 9: 1; 9 1 9; 81 9 1 9 81; 729 81 9 1 9 81 729; ... - Philippe Deléham, Feb 24 2014

			a(1) = 1;
a(2) = 9 + 1 + 9 = 19;
a(3) = 81 + 9 + 1 + 9 + 81 = 181;
a(4) = 729 + 81 + 9 + 1 + 9 + 81 + 729 = 1639; etc. - _Philippe Deléham_, Feb 24 2014

Jiri Herman, Radan Kucera and Jaromir Simsa, Equations and Inequalities, Springer (2000), p. 225 (5.3).

Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (10,-9).

Cf. A000792, A001019, A080926, A084222.

a211866 = (flip div 4) . (subtract 5) . (9 ^)

I:=[1,19]; [n le 2 select I[n] else 10*Self(n-1)-9*Self(n-2): n in [1..25]]; // Vincenzo Librandi, Feb 26 2014

A211866:=n->(9^n-5)/4; seq(A211866(n), n=1..50); # Wesley Ivan Hurt, Nov 13 2013

(9^Range[25] - 5)/4 (* Bruno Berselli, Feb 12 2013 *)
CoefficientList[Series[(1 + 9 x)/((1 - x) (1 - 9 x)), {x, 0, 40}], x] (* Vincenzo Librandi, Feb 26 2014 *)

makelist((9^n-5)/4,n,1,30); /* Martin Ettl, Feb 12 2013 */

a(n)=(9^n-5)/4 \\ Charles R Greathouse IV, Oct 07 2015

G.f.:  x*(1+9*x)/((1-x)*(1-9*x)). - Bruno Berselli, Feb 12 2013
a(n)-a(n-1) = A000792(6n-4). - Bruno Berselli, Feb 12 2013
a(n) = 9*a(n-1) + 10, a(1) = 1. - Philippe Deléham, Feb 24 2014
a(n) = -A084222(2*n). - Philippe Deléham, Feb 24 2014

A087205 a(n) = -2a(n-1) + 4a(n-2), a(0)=1, a(1)=2.

Original entry on oeis.org

1, 2, 0, 8, -16, 64, -192, 640, -2048, 6656, -21504, 69632, -225280, 729088, -2359296, 7634944, -24707072, 79953920, -258736128, 837287936, -2709520384, 8768192512, -28374466560, 91821703168, -297141272576, 961569357824, -3111703805952

Offset: 0

Paul Barry, Aug 25 2003

Inverse binomial transform of A087204.

G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-2,4)

Cf. A000045, A063727, A084222, A085449, A087204.

[(-1)^(n+1)*2^n*Fibonacci(n-2): n in [0..50]]; // G. C. Greubel, Oct 08 2018

Table[-(-2)^n*Fibonacci[n - 2], {n, 0, 50}] (* G. C. Greubel, Oct 08 2018 *)
LinearRecurrence[{-2,4},{1,2},30] (* Harvey P. Dale, Jan 24 2022 *)

Vec((4*x+1)/(-4*x^2+2*x+1)+O(x^66)) \\ Joerg Arndt, Jul 14 2013

vector(50, n, n--; (-1)^(n+1)*2^n*fibonacci(n-2)) \\ G. C. Greubel, Oct 08 2018

a(n) = (-1-sqrt(5))^n * (1/2-3*sqrt(5)/10) + (-1+sqrt(5))^n * (1/2+3*sqrt(5)/10).
G.f.: (4*x +1)/(-4*x^2 +2*x +1). - Joerg Arndt, Jul 14 2013
a(n+2) = A085449(n)*(-1)^(n+1); a(n+3) = A063727(n)*(-1)^n.
a(n) = -(-2)^n*F(n-2) for n >= 0, with F = A000045, and F(-1) = 1, F(-2) = -1. - Wolfdieter Lang, Oct 08 2018

A166114 a(n) = (6-(-4)^n)/5.

Original entry on oeis.org

1, 2, -2, 14, -50, 206, -818, 3278, -13106, 52430, -209714, 838862, -3355442, 13421774, -53687090, 214748366, -858993458, 3435973838, -13743895346, 54975581390, -219902325554, 879609302222, -3518437208882, 14073748835534, -56294995342130

Offset: 0

Philippe Deléham, Oct 06 2009

Georg Fischer, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-3,4).

Cf. A084222, A084247.

Table[(6 - (-4)^n)/5, {n, 0, 100}] (* G. C. Greubel, Apr 24 2016 *)

a(n)=(6-(-4)^n)/5 \\ Charles R Greathouse IV, Apr 28 2016

a(n) = 4*a(n-2) - 3*a(n-1), a(0)= 1, a(1)= 2, for n>1.
a(n) = 6 - 4*a(n-1), a(0)=1.
a(n) = a(n-1) + (-4)^(n-1), a(0)=1.
G.f.: (1+5x)/(1+3x-4x^2).
E.g.f.: (6*exp(x) - exp(-4x))/5.

a(12) onward changed by Georg Fischer, May 03 2019

A166122 a(n) = (7-(-5)^n)/6.

Original entry on oeis.org

1, 2, -3, 22, -103, 522, -2603, 13022, -65103, 325522, -1627603, 8138022, -40690103, 203450522, -1017252603, 5086263022, -25431315103, 127156575522, -635782877603, 3178914388022, -15894571940103, 79472859700522

Offset: 0

Philippe Deléham, Oct 07 2009

G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-4,5).

Cf. A084222, A084247, A166114.

LinearRecurrence[{-4,5},{1,2},30] (* Harvey P. Dale, Mar 10 2016 *)
Table[(7 - (-5)^n)/6, {n, 24}] (* or *)
CoefficientList[Series[(1 + 6 x)/(1 + 4 x - 5 x^2), {x, 0, 24}], x] (* Michael De Vlieger, Apr 27 2016 *)

a(n) = 5*a(n-2) - 4*a(n-1), a(0)= 1, a(1)= 2, for n>1.
a(n) = 7-5*a(n-1), a(0)=1.
a(n) = a(n-1)+(-5)^(n-1), a(0)=1.
O.g.f.: (1+6*x)/(1+4*x-5*x^2).
E.g.f.: (7*exp(x)-exp(-5*x))/6.

A166124 Triangle, read by rows, given by [0,1/2,1/2,0,0,0,0,0,0,0,...] DELTA [2,-1,0,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938.

Original entry on oeis.org

1, 0, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 1, 1, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2

Offset: 0

Philippe Deléham, Oct 07 2009

			Triangle begins :
1 ;
0,2 ;
0,1,2 ;
0,1,1,2 ;
0,1,1,1,2 ;
0,1,1,1,1,2 ;
0,1,1,1,1,1,2 ; ...

Sum_{k, 0<=k<=n} T(n,k)*x^(n-k)= A166122(n), A166114(n), A084222(n), A084247(n), A000034(n), A040000(n), A000027(n+1), A000079(n), A007051(n), A047849(n), A047850(n), A047851(n), A047852(n), A047853(n), A047854(n), A047855(n), A047856(n) for x= -5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10,11 respectively.
Sum_{k, 0<=k<=n} T(n,k)*x^k= A000007(n), A000027(n+1), A033484(n), A134931(n), A083597(n) for x= 0,1,2,3,4 respectively.
T(n,k)= A166065(n,k)/2^(n-k).
G.f.: (1-x+x*y)/(1-x-x*y+x^2*y). - Philippe Deléham, Nov 09 2013
T(n,k) = T(n-1,k) + T(n-1,k-1) - T(n-2,k-1), T(0,0) = 1, T(1,0) = 0, T(1,1) = 2, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Nov 09 2013

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A014983 a(n) = (1 - (-3)^n)/4.

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A084221 a(n+2) = 4*a(n), with a(0)=1, a(1)=3.

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A211866 (9^n - 5) / 4.

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A087205 a(n) = -2*a(n-1) + 4*a(n-2), a(0)=1, a(1)=2.

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A166114 a(n) = (6-(-4)^n)/5.

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A166122 a(n) = (7-(-5)^n)/6.

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A166124 Triangle, read by rows, given by [0,1/2,1/2,0,0,0,0,0,0,0,...] DELTA [2,-1,0,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938.

A087205 a(n) = -2a(n-1) + 4a(n-2), a(0)=1, a(1)=2.