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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A100335 An inverse Catalan transform of J(2n).

Original entry on oeis.org

0, 1, 4, 11, 27, 64, 149, 341, 768, 1707, 3755, 8192, 17749, 38229, 81920, 174763, 371371, 786432, 1660245, 3495253, 7340032, 15379115, 32156331, 67108864, 139810133, 290805077, 603979776, 1252698795, 2594876075, 5368709120
Offset: 0

Views

Author

Paul Barry, Nov 17 2004

Keywords

Comments

The g.f. is obtained from that of A002450 through the mapping g(x) -> g(x*(1-x)). A002450 may be retrieved through the mapping g(x) -> g(x*c(x)), where c(x) is the g.f. of A000108.

Crossrefs

Programs

  • Magma
    I:=[0,1,4,11]; [n le 4 select I[n] else 5*Self(n-1) -9*Self(n-2) +8*Self(n-3) -4*Self(n-4): n in [1..41]]; // G. C. Greubel, Jan 24 2023
    
  • Mathematica
    LinearRecurrence[{5,-9,8,-4}, {0,1,4,11}, 41] (* G. C. Greubel, Jan 24 2023 *)
  • SageMath
    def A100335(n): return (1/3)*((n+1)*2^n - chebyshev_U(n,1/2))
    [A100335(n) for n in range(41)] # G. C. Greubel, Jan 24 2023

Formula

G.f.: x*(1-x)/(1 - 5*x + 9*x^2 - 8*x^3 + 4*x^4).
a(n) = 5*a(n-1) - 9*a(n-2) + 8*a(n-3) - 4*a(n-4).
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k, k)*(-1)^k*(4^(n-k) - 1)/3.
a(n) = (1/3)*((n+1)*2^n - A010892(n)). - Ralf Stephan, May 15 2007
Binomial transform of A042965: (1, 3, 4, 5, 7, 8, 9, 11, 12, 13, ...), also row sums of triangle A133110. - Gary W. Adamson, Sep 12 2007
a(n) = Sum_{k=0..n} A109466(n,k)*A002450(k). - Philippe Deléham, Oct 30 2008

A110517 Riordan array (1,x(1-3x)).

Original entry on oeis.org

1, 0, 1, 0, -3, 1, 0, 0, -6, 1, 0, 0, 9, -9, 1, 0, 0, 0, 27, -12, 1, 0, 0, 0, -27, 54, -15, 1, 0, 0, 0, 0, -108, 90, -18, 1, 0, 0, 0, 0, 81, -270, 135, -21, 1, 0, 0, 0, 0, 0, 405, -540, 189, -24, 1, 0, 0, 0, 0, 0, -243, 1215, -945, 252, -27, 1, 0, 0, 0, 0, 0, 0, -1458, 2835, -1512, 324, -30, 1, 0, 0, 0, 0, 0, 0, 729, -5103, 5670, -2268, 405
Offset: 0

Views

Author

Paul Barry, Jul 24 2005

Keywords

Comments

Inverse is Riordan array (1,xc(3x)) [A110518]. Row sums are A106852. Diagonal sums are A106855.
Modulo 2, this sequence becomes A106344. - Philippe Deléham, Dec 19 2008

Examples

			Rows begin
1;
0, 1;
0, -3, 1;
0, 0, -6, 1;
0, 0, 9, -9, 1;
0, 0, 0, 27, -12, 1;
0, 0, 0, -27, 54, -15, 1;
		

Programs

  • Mathematica
    T[n_, k_] := (-3)^(n - k)*Binomial[k, n - k]; Table[T[n, k], {n, 0, 20}, {k, 0, n}] // Flatten (* G. C. Greubel, Aug 29 2017 *)
  • PARI
    for(n=0,20, for(k=0,n, print1((-3)^(n-k)*binomial(k, n-k), ", "))) \\ G. C. Greubel, Aug 29 2017

Formula

Number triangle: T(n, k) = (-3)^(n-k)*binomial(k, n-k).
T(n,k) = A109466(n,k)*3^(n-k). - Philippe Deléham, Oct 26 2008

A146078 Expansion of 1/(1-x*(1-9*x)).

Original entry on oeis.org

1, 1, -8, -17, 55, 208, -287, -2159, 424, 19855, 16039, -162656, -307007, 1156897, 3919960, -6492113, -41771753, 16657264, 392603041, 242687665, -3290739704, -5474928689, 24141728647, 73416086848, -143859470975, -804604252607
Offset: 0

Views

Author

Philippe Deléham, Oct 27 2008

Keywords

Comments

Row sums of Riordan array (1, x(1-9x)).

Crossrefs

Programs

  • Magma
    I:=[1,1]; [n le 2 select I[n] else Self(n-1) - 9*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 19 2018
  • Mathematica
    LinearRecurrence[{1, -9}, {1, 1}, 100] (* G. C. Greubel, Jan 30 2016 *)
  • PARI
    x='x+O('x^30); Vec(1/(1-x+9*x^2)) \\ G. C. Greubel, Jan 19 2018
    
  • Sage
    [lucas_number1(n,1,9) for n in range(1, 27)] # Zerinvary Lajos, Apr 22 2009
    

Formula

a(n) = a(n-1) - 9*a(n-2), a(0)=1, a(1)=1.
a(n) = Sum_{k=0..n} A109466(n,k)*9^(n-k).
From G. C. Greubel, Jan 31 2016: (Start)
G.f.: 1/(1-x+9*x^2).
E.g.f.: exp(x/2)*(cos(sqrt(35)*x/2) + (1/sqrt(35))*sin(sqrt(35)*x/2)). (End)
a(n) = Product_{k=1..n} (1 + 6*cos(k*Pi/(n+1))). - Peter Luschny, Nov 28 2019
a(n) = 3^n * U(n, 1/6), where U(n, x) is the Chebyshev polynomial of the second kind. - Federico Provvedi, Mar 28 2022

A146080 Expansion of 1/(1-x*(1-10*x)).

Original entry on oeis.org

1, 1, -9, -19, 71, 261, -449, -3059, 1431, 32021, 17711, -302499, -479609, 2545381, 7341471, -18112339, -91527049, 89596341, 1004866831, 108903421, -9939764889, -11028799099, 88368849791, 198656840781, -685031657129, -2671600064939
Offset: 0

Views

Author

Philippe Deléham, Oct 27 2008

Keywords

Comments

Row sums of Riordan array (1,x(1-10x)).

Programs

  • Magma
    I:=[1,1]; [n le 2 select I[n] else Self(n-1) - 10*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 19 2018
  • Mathematica
    CoefficientList[Series[1/(1-x(1-10x)),{x,0,30}],x] (* or *) LinearRecurrence[{1,-10},{1,1},30] (* Harvey P. Dale, Dec 16 2012 *)
  • PARI
    Vec(1/(1-x*(1-10*x))+O(x^99)) \\ Charles R Greathouse IV, Jan 12 2012
    
  • Sage
    [lucas_number1(n,1,10) for n in range(1, 27)] # Zerinvary Lajos, Apr 22 2009
    

Formula

a(n) = a(n-1) - 10*a(n-2), a(0)=1, a(1)=1.
a(n) = Sum_{k=0..n} A109466(n,k)*10^(n-k).
E.g.f.: exp(x/2)*(cos(sqrt(39)*x/2) + (1/sqrt(39))*sin(sqrt(39)*x/2)). - G. C. Greubel, Jan 30 2016

A106233 An inverse Catalan transform of A003462.

Original entry on oeis.org

0, 1, 3, 5, 5, 0, -14, -41, -81, -121, -121, 0, 364, 1093, 2187, 3281, 3281, 0, -9842, -29525, -59049, -88573, -88573, 0, 265720, 797161, 1594323, 2391485, 2391485, 0, -7174454, -21523361, -43046721, -64570081, -64570081, 0, 193710244, 581130733, 1162261467
Offset: 0

Views

Author

Paul Barry, Apr 26 2005

Keywords

Comments

The g.f. is obtained from that of A003462 through the mapping g(x)->g(x(1-x)). A003462 may be retrieved through the mapping g(x)->g(xc(x)), where c(x) is the g.f. of A000108. Binomial transform of x(1+x)/(1+x^2+x^4).
The sequence is identical to its sixth differences. See A140344. - Paul Curtz, Nov 09 2012

Examples

			From _Paul Curtz_, Nov 09 2012: (Start)
The sequence and its higher-order differences (periodic after 6 rows):
   0,  1,  3,  5,  5,   0, -14, ...
   1,  2,  2,  0, -5, -14, -27, ...
   1,  0, -2, -5, -9, -13, -13, ...
  -1, -2, -3, -4, -4,   0,  13, ...   = -A134581(n+1)
  -1, -1, -1,  0,  4,  13,  27, ...
   0,  0,  1,  4,  9,  14,  14, ...   = A140343(n+2)
   0,  1,  3,  5,  5,   0, -14, ...
(End)
		

Crossrefs

Cf. A103368.

Programs

  • Magma
    I:=[0,1,3,5]; [n le 4 select I[n] else 4*Self(n-1)-7*Self(n-2)+ 6*Self(n-3)-3*Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 24 2018
  • Mathematica
    LinearRecurrence[{4, -7, 6, -3}, {0, 1, 3, 5}, 35] (* Vincenzo Librandi, Dec 24 2018 *)

Formula

G.f.: x(1-x)/((1-x+x^2)*(1-3*x+3*x^2));
a(n) = Sum_{k=0..floor(n/2)} C(n-k, k)*(-1)^k*(3^(n-k)-1)/2.
a(n) = Sum_{k=0..n} A109466(n,k)*A003462(k). - Philippe Deléham, Oct 30 2008
a(n) = (1/2)*[A057083(n) - [1,1,0,0,-1,-1]6 ]. - _Ralf Stephan, Nov 15 2010
a(n) = 4*a(n-1) - 7*a(n-2) + 6*a(n-3) - 3*a(n-4) = A140343(n+2) - A140343(n+1). - Paul Curtz, Nov 09 2012
a(n) is the binomial transform of the sequence 0, 1, 1, -1, -1, 0, ... = A103368(n+5). - Paul Curtz, Nov 09 2012

A146083 Expansion of 1/(1 - x*(1 - 11*x)).

Original entry on oeis.org

1, 1, -10, -21, 89, 320, -659, -4179, 3070, 49039, 15269, -524160, -692119, 5073641, 12686950, -43123101, -182679551, 291674560, 2301149621, -907270539, -26219916370, -16239940441, 272179139629, 450818484480, -2543152051439
Offset: 0

Views

Author

Philippe Deléham, Oct 27 2008

Keywords

Comments

Row sums of Riordan array (1,x(1-11x)).

Crossrefs

Programs

Formula

a(n) = a(n-1)-11*a(n-2) ; a(0)=1, a(1)=1.
a(n) = Sum_{k=0..n} A109466(n,k)*11^(n-k).
From G. C. Greubel, Jan 31 2016: (Start)
G.f.: 1/(1-x+11*x^2).
E.g.f.: exp(x/2)*(cos(sqrt(43)*x/2) + (1/sqrt(43))*sin(sqrt(43)*x/2)).
(End)

A146541 Binomial transform of A010688.

Original entry on oeis.org

1, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648, 4294967296, 8589934592
Offset: 0

Views

Author

Philippe Deléham, Oct 31 2008

Keywords

Comments

Hankel transform is := 1,-48,0,0,0,0,0,0,0,...

Crossrefs

Programs

  • Mathematica
    Join[{1},2^Range[3,40]] (* Harvey P. Dale, Feb 28 2016 *)
  • PARI
    Vec((1+6*x)/(1-2*x) + O(x^50)) \\ Colin Barker, Mar 17 2016

Formula

a(0)=1, a(n) = 2^(n+2) for n>0.
a(n) = Sum_{k, 0..n} A109466(n,k)*A146534(k).
a(n) = A132479(n), n>1. - R. J. Mathar, Nov 02 2008
G.f.: (1+6*x) / (1-2*x). - Colin Barker, Mar 17 2016

Extensions

Corrected and extended by Harvey P. Dale, Feb 28 2016

A099322 An inverse Catalan transform of J(3n)/J(3).

Original entry on oeis.org

0, 1, 6, 43, 291, 1992, 13595, 92845, 633966, 4329023, 29560367, 201850896, 1378323999, 9411785201, 64267689006, 438847231427, 2996636337771, 20462312853336, 139725412120339, 954104794142789, 6515035056168654
Offset: 0

Views

Author

Paul Barry, Nov 17 2004

Keywords

Comments

The g.f. is obtained from that of A015565 through the mapping g(x)->g(x(1-x)). A015565 may be retrieved through the mapping g(x)->g(xc(x)), where c(x) is the g.f. of A000108.

Crossrefs

Cf. A001045.

Programs

  • Mathematica
    LinearRecurrence[{7,1,-16,8},{0,1,6,43},30] (* Harvey P. Dale, Jul 19 2016 *)

Formula

G.f.: x(1-x)/(1-7x-x^2+16x^3-8x^4);
a(n) = 7a(n-1) + a(n-2) - 16a(n-3) + 8a(n-4);
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k, k)*(-1)^k*J(3n-3k)/J(3).
a(n) = Sum_{k=0..n} A109466(n,k)*A015565(k). - Philippe Deléham, Oct 30 2008

A146084 Expansion of 1/(1-x(1-12x)).

Original entry on oeis.org

1, 1, -11, -23, 109, 385, -923, -5543, 5533, 72049, 5653, -858935, -926771, 9380449, 20501701, -92063687, -338084099, 766680145, 4823689333, -4376472407, -62260744403, -9743075519, 737385857317, 854302763545, -7994327524259
Offset: 0

Views

Author

Philippe Deléham, Oct 27 2008

Keywords

Comments

Row sums of Riordan array (1,x(1-12x)).

Crossrefs

Programs

Formula

a(n) = a(n-1)-12*a(n-2), a(0)=1, a(1)=1.
a(n) = Sum_{k, 0<=k<=n} A109466(n,k)*12^(n-k).

A164925 Array, binomial(j-i,j), read by rising antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, -1, 0, 1, 1, -2, 0, 0, 1, 1, -3, 1, 0, 0, 1, 1, -4, 3, 0, 0, 0, 1, 1, -5, 6, -1, 0, 0, 0, 1, 1, -6, 10, -4, 0, 0, 0, 0, 1, 1, -7, 15, -10, 1, 0, 0, 0, 0, 1, 1, -8, 21, -20, 5, 0, 0, 0, 0, 0, 1, 1, -9, 28, -35, 15, -1, 0, 0, 0, 0, 0, 1, 1, -10, 36, -56, 35, -6, 0, 0, 0, 0, 0, 0, 1
Offset: 0

Views

Author

Mark Dols, Aug 31 2009

Keywords

Comments

Inverse of A052509, or A004070???

Examples

			Array, A(n, k), begins as:
  1,  1,  1,   1,  1,   1,  1,  1,  1, ...
  1,  0,  0,   0,  0,   0,  0,  0,  0, ...
  1, -1,  0,   0,  0,   0,  0,  0,  0, ...
  1, -2,  1,   0,  0,   0,  0,  0,  0, ...
  1, -3,  3,  -1,  0,   0,  0,  0,  0, ...
  1, -4,  6,  -4,  1,   0,  0,  0,  0, ...
  1, -5, 10, -10,  5,  -1,  0,  0,  0, ...
  1, -6, 15, -20, 15,  -6,  1,  0,  0, ...
  1, -7, 21, -35, 35, -21,  7, -1,  0, ...
Antidiagonal triangle, T(n, k), begins as:
  1;
  1,  1;
  1,  0,  1;
  1, -1,  0,  1;
  1, -2,  0,  0,  1;
  1, -3,  1,  0,  0,  1;
  1, -4,  3,  0,  0,  0,  1;
  1, -5,  6, -1,  0,  0,  0,  1;
  1, -6, 10, -4,  0,  0,  0,  0,  1;
		

Crossrefs

Programs

  • Magma
    A164925:= func< n,k | k eq 0 or k eq n select 1 else Binomial(2*k-n,k) >;
    [A164925(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Feb 10 2023
    
  • Mathematica
    T[n_, k_]:= If[k==0 || k==n, 1, Binomial[2*k-n, k]];
    Table[T[n,k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Feb 10 2023 *)
  • PARI
    {A(i, j) = if( i<0, 0, if(i==0 || j==0, 1, binomial(j-i, j)))}; /* Michael Somos, Jan 25 2012 */
    
  • SageMath
    def A164925(n,k): return 1 if (k==0 or k==n) else binomial(2*k-n, k)
    flatten([[A164925(n,k) for k in range(n+1)] for n in range(13)]) # G. C. Greubel, Feb 10 2023

Formula

Sum_{k=0..n} T(n, k) = A164965(n). - Mark Dols, Sep 02 2009
From G. C. Greubel, Feb 10 2023: (Start)
A(n, k) = binomial(k-n, k), with A(0, k) = A(n, 0) = 1 (array).
T(n, k) = binomial(2*k-n, k), with T(n, 0) = T(n, n) = 1 (antidiagonal triangle).
Sum_{k=0..n} (-1)^k*T(n, k) = A008346(n).
Sum_{k=0..n} (-2)^k*T(n, k) = (-1)^n*A052992(n). (End)

Extensions

Edited by Michael Somos, Jan 26 2012
Offset changed by G. C. Greubel, Feb 10 2023
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