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.

Previous Showing 11-17 of 17 results.

A073383 Sixth convolution of A000129(n+1) (generalized (2,1)-Fibonacci, called Pell numbers), n>=0, with itself.

Original entry on oeis.org

1, 14, 119, 784, 4396, 22008, 101220, 435696, 1777986, 6943244, 26129950, 95282992, 338108876, 1171554776, 3975215844, 13239402960, 43364985867, 139925413866, 445409413421, 1400429394784, 4353771487912
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Crossrefs

Seventh (m=6) column of triangle A054456, A073382.
Cf. A000129.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/(1-2*x-x^2)^7 )); // G. C. Greubel, Oct 02 2022
    
  • Mathematica
    CoefficientList[Series[1/(1-2*x-x^2)^7, {x,0,70}], x] (* G. C. Greubel, Oct 02 2022 *)
    LinearRecurrence[{14,-77,196,-161,-238,427,184,-427,-238,161,196,77,14,1},{1,14,119,784,4396,22008,101220,435696,1777986,6943244,26129950,95282992,338108876,1171554776},30] (* Harvey P. Dale, Apr 26 2025 *)
  • SageMath
    def A073383_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/(1-2*x-x^2)^7 ).list()
    A073383_list(40) # G. C. Greubel, Oct 02 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A000129(k+1) and c(k) = A073382(k).
a(n) = Sum_{k=0..floor(n/2)} 2^(n-2*k) * binomial(n-k+6, 6) * binomial(n-k, k).
a(n) = (7*(173205 +212028*n +96812*n^2 +20728*n^3 +2092*n^4 +80*n^5)*(n+1)* U(n+1) + (262125 +435150*n +232364*n^2 +54548*n^3 +5836*n^4 +232*n^5)*(n+2)* U(n) )/(6!*8^4), with U(n) = A000129(n+1), n >= 0.
G.f.: 1/(1-(2+x)*x)^7.
a(n) = F''''''(n+7, 2)/6!, that is, 1/6! times the 6th derivative of the (n+7)-th Fibonacci polynomial evaluated at x=2. - T. D. Noe, Jan 19 2006

A073384 Seventh convolution of A000129(n+1) (generalized (2,1)-Fibonacci, called Pell numbers), n>=0, with itself.

Original entry on oeis.org

1, 16, 152, 1104, 6756, 36624, 181224, 834768, 3628746, 15035504, 59829704, 229977904, 857894388, 3117321456, 11067753144, 38492230704, 131417200419, 441252045408, 1459330704656, 4760342849504
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Crossrefs

Eighth (m=7) column of triangle A054456, A073383.
Cf. A000129.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/(1-2*x-x^2)^8 )); // G. C. Greubel, Oct 03 2022
    
  • Mathematica
    CoefficientList[Series[1/(1-2*x-x^2)^8, {x,0,40}], x] (* G. C. Greubel, Oct 03 2022 *)
  • SageMath
    def A073384_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/(1-2*x-x^2)^8 ).list()
    A073384_list(40) # G. C. Greubel, Oct 03 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A000129(k+1) and c(k) = A073383(k).
a(n) = Sum_{k=0..floor(n/2)} 2^(n-2*k) * binomial(n-k+7, 7) * binomial(n-k, k).
a(n) = ((34083315 +46659654*n +24858030*n^2 +6632968*n^3 +939632*n^4 +67304*n^5 + 1912*n^6)*(n+1)*U(n+1) + (7204365 +13225068*n +8230910*n^2 +2411744*n^3 + 362968*n^4 +27088*n^5 +792*n^6)*(n+2)*U(n))/(2^18*3^2*5*7), with U(n) = A000129(n+1), n >= 0.
G.f.: 1/(1-(2+x)*x)^8.
a(n) = F'''''''(n+8, 2)/7!, that is, 1/7! times the 7th derivative of the (n+8)-th Fibonacci polynomial evaluated at x=2. - T. D. Noe, Jan 19 2006

A073385 Eighth convolution of A000129(n+1) (generalized (2,1)-Fibonacci, called Pell numbers), n>=0, with itself.

Original entry on oeis.org

1, 18, 189, 1500, 9945, 58014, 307197, 1507176, 6950295, 30443270, 127666539, 515754252, 2017069431, 7667214570, 28419251715, 102997948704, 365832349542, 1275914693196, 4376992440590
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Comments

For a(n) in terms of U(n+1) and U(n) with U(n) = A000129(n+1) see the row polynomials of triangles A058402 and A058403 and the comment there.

Crossrefs

Ninth (m=8) column of triangle A054456.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/(1-2*x-x^2)^9 )); // G. C. Greubel, Oct 03 2022
  • Mathematica
    CoefficientList[Series[1/(1-(2+x)x)^9,{x,0,20}],x] (* Harvey P. Dale, Apr 26 2017 *)
  • Sage
    taylor( 1/(1-2*x-x^2)^9, x, 0,27).list() # G. C. Greubel, Oct 03 2022
    

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A000129(k+1) and c(k) = A073384(k).
a(n) = Sum_{k=0..floor(n/2)} 2^(n-2*k)*binomial(n-k+8, 8)*binomial(n-k, k).
G.f.: 1/(1-(2+x)*x)^9.
a(n) = F''''''''(n+9, 2)/8!, that is, 1/8! times the 8th derivative of the (n+9)-th Fibonacci polynomial evaluated at x=2. - T. D. Noe, Jan 19 2006

A112899 A skew Pell-Pascal triangle.

Original entry on oeis.org

1, 0, 2, 0, 1, 5, 0, 0, 4, 12, 0, 0, 1, 14, 29, 0, 0, 0, 6, 44, 70, 0, 0, 0, 1, 27, 131, 169, 0, 0, 0, 0, 8, 104, 376, 408, 0, 0, 0, 0, 1, 44, 366, 1052, 985, 0, 0, 0, 0, 0, 10, 200, 1212, 2888, 2378, 0, 0, 0, 0, 0, 1, 65, 810, 3842, 7813, 5741, 0, 0, 0, 0, 0, 0, 12, 340, 3032, 11784
Offset: 0

Views

Author

Paul Barry, Oct 05 2005

Keywords

Comments

Main diagonal is A000129. Row sums are A002605. Column sums are A006190(n+1).
A skewed version of the Riordan array (1/(1-2x-x^2), x/(1-2x-x^2)), see A054456. - Philippe Deléham, Nov 21 2007
Triangle, read by rows, given by [0,1/2,-1/2,0,0,0,0,0,...] DELTA [2,1/2,-1/2,0,0,0,0,0,...] where DELTA is the operator defined in A084938. - Philippe Deléham, Jan 30 2010

Examples

			Rows begin:
  1;
  0,   2;
  0,   1,   5;
  0,   0,   4,  12;
  0,   0,   1,  14,  29;
  0,   0,   0,   6,  44,  70;
  0,   0,   0,   1,  27, 131, 169;
  0,   0,   0,   0,   8, 104, 376, 408;
		

Crossrefs

Cf. A111006, A112906. - Philippe Deléham, Jan 30 2010

Formula

G.f.: 1/(1-2*x*y*(1+x/2)-x^2*y^2).
T(n, k) = Sum_{j=0..floor((2*k-n)/2)} C(k-j, n-k)*C(2*k-n-j, j)*2^(2*k-2*j-n). [corrected by Jason Yuen, Jan 21 2025]
T(n, k) = 2*T(n-1, k-1) + T(n-2, k-1) + T(n-2, k-2).

A058405 Coefficient triangle of polynomials (falling powers) related to Pell number convolutions. Companion triangle is A058404.

Original entry on oeis.org

2, 8, 20, 48, 288, 360, 320, 3520, 11360, 9840, 2176, 37888, 225344, 522752, 363360, 14848, 373504, 3491072, 14871296, 27849600, 16776000, 101376, 3467264, 46459904, 308703232, 1053556480, 1692808704, 922158720, 692224, 30834688
Offset: 0

Views

Author

Wolfdieter Lang, Dec 11 2000

Keywords

Comments

The row polynomials are q(k,x) := sum(a(k,m)*x^(k-m),m=0..k), k=0,1,2,..
The k-th convolution of P0(n) := A000129(n+1), n >= 0, (Pell numbers starting with P0(0)=1) with itself is Pk(n) := A054456(n+k,k) = (p(k-1,n)*(n+1)*2*P0(n+1) + q(k-1,n)*(n+2)*P0(n))/(k!*8^k), k=1,2,..., where the companion polynomials p(k,n) := sum(b(k,m)*n^(k-m),m=0..k) are the row polynomials of triangle b(k,m)= A058404(k,m).

Examples

			k=2: P2(n)=((8*n+22)*(n+1)*2*P0(n+1)+(8*n+20)*(n+2)*P0(n))/128, cf. A054457.
2; 8,20; 48,288,360; ... (lower triangular matrix a(k,m), k >= m >= 0, else 0)
		

Crossrefs

Cf. A000129, A054456, A058404, A054457, A058402-3 (rising powers).

Formula

Recursion for row polynomials defined in the comments: see A058402.

Extensions

Link and cross-references added by Wolfdieter Lang, Jul 31 2002

A073386 Ninth convolution of A000129(n+1) (generalized (2,1)-Fibonacci, called Pell numbers), n>=0, with itself.

Original entry on oeis.org

1, 20, 230, 1980, 14135, 88264, 497860, 2591160, 12630475, 58295380, 256887774, 1087825180, 4449607565, 17654254880, 68177369040, 257006941664, 948023601910, 3428968838680, 12182953719860
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Comments

For a(n) in terms of U(n+1) and U(n) with U(n) = A000129(n+1) see the row polynomials of triangles A058402 and A058403 and the comment there.

Crossrefs

Tenth (m=9) column of triangle A054456.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/(1-2*x-x^2)^10 )); // G. C. Greubel, Oct 03 2022
    
  • Mathematica
    CoefficientList[Series[1/(1-2*x-x^2)^10, {x,0,40}], x] (* G. C. Greubel, Oct 03 2022 *)
    LinearRecurrence[{20,-170,780,-1965,2064,1800,-6480,1710,8600,-3772,-8600,1710,6480,1800,-2064,-1965,-780,-170,-20,-1},{1,20,230,1980,14135,88264,497860,2591160,12630475,58295380,256887774,1087825180,4449607565,17654254880,68177369040,257006941664,948023601910,3428968838680,12182953719860,42585118702280},20] (* Harvey P. Dale, Nov 20 2022 *)
  • SageMath
    def A073386_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/(1-2*x-x^2)^10 ).list()
    A073386_list(40) # G. C. Greubel, Oct 03 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A000129(k+1) and c(k) = A073385(k).
a(n) = Sum_{k=0..floor(n/2)} 2^(n-2*k)*binomial(n-k+9, 9)*binomial(n-k, k).
G.f.: 1/(1-(2+x)*x)^10.
a(n) = F'''''''''(n+10, 2)/9!, that is, 1/9! times the 9th derivative of the (n+10)th Fibonacci polynomial evaluated at x=2. - T. D. Noe, Jan 19 2006

A132964 Convolution triangle of A006190.

Original entry on oeis.org

1, 3, 1, 10, 6, 1, 33, 29, 9, 1, 109, 126, 57, 12, 1, 360, 516, 306, 94, 15, 1, 1189, 2034, 1491, 600, 140, 18, 1, 3927, 7807, 6813, 3385, 1035, 195, 21, 1, 12970, 29382, 29737, 17568, 6630, 1638, 259, 24, 1, 42837, 108923, 125406, 85826, 38493, 11739, 2436, 332, 27, 1
Offset: 0

Views

Author

Philippe Deléham, Nov 24 2007

Keywords

Comments

As a Riordan array, this is (1/(1-3x-x^2),x/(1-3x-x^2)).
T(n,k) is the number of words of length n over {0,1,2,3,4} having k letters 4 and avoiding runs of odd length for the letter 0. - Milan Janjic, Jan 14 2017

Examples

			Triangle begins:
      1;
      3,      1;
     10,      6,      1;
     33,     29,      9,     1;
    109,    126,     57,    12,     1;
    360,    516,    306,    94,    15,     1;
   1189,   2034,   1491,   600,   140,    18,    1;
   3927,   7807,   6813,  3385,  1035,   195,   21,   1;
  12970,  29382,  29737, 17568,  6630,  1638,  259,  24,  1;
  42837, 108923, 125406, 85826, 38493, 11739, 2436, 332, 27, 1;
  ...
		

Crossrefs

Formula

Sum_{k=0..n} T(n,k) = A001076(n+1).
Sum_{k=0..floor(n/2)} T(n-k,k) = A007482(n).
T(n,k) = 3*T(n-1,k) + T(n-1,k-1) + T(n-2,k), T(0,0)=1, T(n,k)=0 if k<0 or k>n. - Philippe Deléham, Dec 08 2013
Previous Showing 11-17 of 17 results.