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 11-18 of 18 results.

A073377 Seventh convolution of A001045(n+1) (generalized (1,2)-Fibonacci), n>=0, with itself.

Original entry on oeis.org

1, 8, 52, 264, 1194, 4872, 18516, 66264, 226083, 740608, 2344232, 7202416, 21562164, 63090288, 180884088, 509245776, 1410356133, 3848340312, 10359516684, 27544099704, 72406891326, 188356187448
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Crossrefs

Eighth (m=7) column of triangle A073370.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/((1+x)*(1-2*x))^8 )); // G. C. Greubel, Sep 29 2022
    
  • Mathematica
    Table[(2^(n+8)*(9539600 +17240268*n +11555460*n^2 +3849489*n^3 +703080*n^4 +71442*n^5 +3780*n^6 +81*n^7) +(-1)^n*(236325040 +225702732*n +87290028*n^2 +17880849*n^3 +2109240*n^4 +144018*n^5 +5292*n^6 +81*n^7))/(7!*3^12), {n,0,60}] (* G. C. Greubel, Sep 29 2022 *)
  • SageMath
    def A073377(n): return (2^(n+8)*(9539600 +17240268*n +11555460*n^2 +3849489*n^3 +703080*n^4 +71442*n^5 +3780*n^6 +81*n^7) +(-1)^n*(236325040 +225702732*n +87290028*n^2 +17880849*n^3 +2109240*n^4 +144018*n^5 +5292*n^6 +81*n^7))/(factorial(7)*3^12)
    [A073377(n) for n in range(40)] # G. C. Greubel, Sep 29 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A001045(k+1) and c(k) = A073376(k).
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k+7, 7) * binomial(n-k, k) * 2^k.
a(n) = ((328247920 +332102604*n +131833680*n^2 +26450901*n^3 +2844099*n^4 + 156087*n^5 +3429*n^6)*(n+1)*U(n+1) + 2(141143240 +150941694*n +62335731*n^2 + 12873492*n^3 +1414314*n^4 +78894*n^5 +1755*n^6)*(n+2)*U(n))/(7!*3^11) with U(n) = A001045(n+1), n>=0.
G.f.: 1/(1-(1+2*x)*x)^8 = 1/((1+x)*(1-2*x))^8.
E.g.f.: (1/(7!*3^12))*( 4096*(596225 +4177950*x +7304850*x^2 +5109300*x^3 +1691550*x^4 +278964*x^5 +21924*x^6 +648*x^7)*exp(2*x) + (236325040 -333132240*x +158026680*x^2 -34637400*x^3 +3921750*x^4 -234738*x^5 +6993*x^6 -81*x^7)*exp(-x) ). - G. C. Greubel, Sep 29 2022

A073378 Eighth convolution of A001045(n+1) (generalized (1,2)-Fibonacci), n>=0, with itself.

Original entry on oeis.org

1, 9, 63, 345, 1665, 7227, 29073, 109791, 394020, 1354210, 4486482, 14397318, 44932446, 136817370, 407566350, 1190446866, 3415935699, 9645169743, 26836557825, 73670997015, 199751003991, 535449185469
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) = A001045(n+1) see A073370 and the row polynomials of triangles A073399 and A073400.

Crossrefs

Ninth (m=8) column of triangle A073370.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/((1+x)*(1-2*x))^9 )); // G. C. Greubel, Oct 01 2022
    
  • Mathematica
    CoefficientList[Series[1/((1+x)*(1-2*x))^9, {x,0,40}], x] (* G. C. Greubel, Oct 01 2022 *)
  • SageMath
    def A073378_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1+x)*(1-2*x))^9 ).list()
    A073378_list(40) # G. C. Greubel, Oct 01 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A001045(k+1) and c(k) = A073377(k).
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k+8, 8) * binomial(n-k, k) * 2^k.
G.f.: 1/(1-(1+2*x)*x)^9 = 1/((1+x)*(1-2*x))^9.

A073402 Coefficient triangle of polynomials (rising powers) related to convolutions of A001045(n+1), n >= 0, (generalized (1,2)-Fibonacci). Companion triangle is A073401.

Original entry on oeis.org

2, 33, 9, 831, 396, 45, 28236, 18297, 3744, 243, 1210140, 968679, 273483, 32481, 1377, 62686440, 58920534, 20681811, 3418767, 268029, 8019, 3810867480, 4075425738, 1683064737, 347584284, 38186478, 2130138, 47385
Offset: 0

Views

Author

Wolfdieter Lang, Aug 02 2002

Keywords

Comments

The row polynomials are q(k,x) := sum(a(k,m)*x^m,m=0..k), k=0,1,2,...
The k-th convolution of U0(n) := A001045(n+1), n>= 0, ((1,2) Fibonacci numbers starting with U0(0)=1) with itself is Uk(n) := A073370(n+k,k) = (p(k-1,n)*(n+1)*U0(n+1) + q(k-1,n)*(n+2)*2*U0(n))/(k!*9^k)), k=1,2,..., where the companion polynomials p(k,n) := sum(b(k,m)*n^m,m=0..k), k >= 0, are the row polynomials of triangle b(k,m)= A073401(k,m).

Examples

			k=2: U2(n)=((30+9*n)*(n+1)*U0(n+1)+(33+9*n)*(n+2)*2*U0(n))/(2*9^2), cf. A073372.
1; 33,9; 831,396,45; ... (lower triangular matrix a(k,m), k >= m >= 0, else 0).
		

Crossrefs

Formula

Recursion for row polynomials defined in the comments: p(k, n)= (n+2)*p(k-1, n+1)+4*(n+2*(k+1))*p(k-1, n)+2*(n+3)*q(k-1, n+1); q(k, n)= (n+1)*p(k-1, n+1)+4*(n+2*(k+1))*q(k-1, n), k >= 1. [Corrected by Sean A. Irvine, Nov 25 2024]

A073379 Ninth convolution of A001045(n+1) (generalized (1,2)-Fibonacci), n>=0, with itself.

Original entry on oeis.org

1, 10, 75, 440, 2255, 10362, 43945, 174460, 656370, 2359500, 8158722, 27275040, 88524930, 279892380, 864508590, 2614740216, 7759693095, 22634343270, 64990287285, 183929970840, 513661549401, 1416970676550
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) = A001045(n+1), see A073370 and the row polynomials of triangles A073399 and A073400.

Crossrefs

Tenth (m=9) column of triangle A073370.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/((1+x)*(1-2*x))^10 )); // G. C. Greubel, Oct 01 2022
    
  • Mathematica
    CoefficientList[Series[1/((1+x)*(1-2*x))^10, {x,0,40}], x] (* G. C. Greubel, Oct 01 2022 *)
  • SageMath
    def A073379_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1+x)*(1-2*x))^10 ).list()
    A073379_list(40) # G. C. Greubel, Oct 01 2022

Formula

a(n) = Sum_{k=0..n} b(k)*c(n-k), with b(k) = A001045(k+1) and c(k) = A073378(k).
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k+9, 9) * binomial(n-k, k) * 2^k.
G.f.: 1/(1-(1+2*x)*x)^10 = 1/((1+x)*(1-2*x))^10.

A125693 Riordan array ((1-x)/(1-3*x), x*(1-x)/(1-3*x)).

Original entry on oeis.org

1, 2, 1, 6, 4, 1, 18, 16, 6, 1, 54, 60, 30, 8, 1, 162, 216, 134, 48, 10, 1, 486, 756, 558, 248, 70, 12, 1, 1458, 2592, 2214, 1168, 410, 96, 14, 1, 4374, 8748, 8478, 5160, 2150, 628, 126, 16, 1, 13122, 29160, 31590, 21744, 10442, 3624, 910, 160, 18, 1
Offset: 0

Views

Author

Paul Barry, Nov 30 2006

Keywords

Comments

Row sums are A001835(n+1). Diagonal sums are A030186. Inverse is A125694. Equal to product of A007318 and A073370.

Examples

			Triangle begins
    1;
    2,   1;
    6,   4,   1;
   18,  16,   6,  1;
   54,  60,  30,  8,  1;
  162, 216, 134, 48, 10, 1;
		

Programs

  • GAP
    Flat(List([0..10], n-> List([0..n], k-> Sum([0..n], j->
    (-1)^j*3^(n-k-j)*Binomial(k+1,j)*Binomial(n-j, n-k-j) )))); # G. C. Greubel, Oct 28 2019
  • Magma
    T:= func< n,k | &+[(-1)^j*3^(n-k-j)*Binomial(k+1,j)*Binomial(n-j, n-k-j): j in [0..n]] >;
    [T(n,k): k in [0..n], n in [0..10]]; // G. C. Greubel, Oct 28 2019
    
  • Maple
    seq(seq( add( (-1)^j*3^(n-k-j)*binomial(k+1,j)*binomial(n-j, n-k-j), j=0..n), k=0..n), n=0..10); # G. C. Greubel, Oct 28 2019
  • Mathematica
    T[0, 0]=1; T[1, 0]=2; T[1, 1]=1; T[n_, k_]/; 0<=k<=n:= T[n, k]= 3T[n-1, k] + T[n-1, k-1] - T[n-2, k-1]; T[, ]=0; Table[T[n, k], {n, 0, 9}, {k, 0, n}] (* Jean-François Alcover, Jun 13 2019 *)
    T[n_, k_]:= Sum[(-1)^j*3^(n-k-j)*Binomial[k+1,j]*Binomial[n-j,n-k-j], {j, 0, n}]; Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Oct 28 2019 *)
  • PARI
    T(n,k) = sum(j=0,n, (-1)^j*3^(n-k-j)*binomial(k+1,j)*binomial(n-j, n-k-j));
    for(n=0,10, for(k=0,n, print1(T(n,k), ", "))) \\ G. C. Greubel, Oct 28 2019
    
  • Sage
    [[sum( (-1)^j*3^(n-k-j)*binomial(k+1,j)*binomial(n-j, n-k-j) for j in (0..n) ) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Oct 28 2019
    

Formula

Number triangle T(n,k) = Sum_{j=0..k+1} C(k+1,j)*C(n-j,n-k-j)* (-1)^j * 3^(n-k-j).
T(n,k) = 3*T(n-1,k) + T(n-1,k-1) - T(n-2,k-1), T(0,0)=1, T(1,0)=2, T(1,1)=1, T(n,k)=0 if k>n or if kPhilippe Deléham, Jan 08 2013

A112883 A skew Jacobsthal-Pascal matrix.

Original entry on oeis.org

1, 0, 1, 0, 1, 3, 0, 0, 2, 5, 0, 0, 1, 7, 11, 0, 0, 0, 3, 16, 21, 0, 0, 0, 1, 12, 41, 43, 0, 0, 0, 0, 4, 34, 94, 85, 0, 0, 0, 0, 1, 18, 99, 219, 171, 0, 0, 0, 0, 0, 5, 60, 261, 492, 341, 0, 0, 0, 0, 0, 1, 25, 195, 678, 1101, 683, 0, 0, 0, 0, 0, 0, 6, 95, 576, 1692, 2426, 1365, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Paul Barry, Oct 05 2005

Keywords

Comments

T(n,n) is A001045(n), row sums are A006130, column sums are A002605. Compare with [0,1,-1,0,0,..] DELTA [1,2,-2,0,0,...] where DELTA is the operator defined in A084938. A skewed version of the Riordan array (1/(1-x-2x^2),x/(1-x-2x^2)) (A073370).
Modulo 2, this sequence gives A106344. - Philippe Deléham, Dec 18 2008

Examples

			Rows begin
  1;
  0, 1;
  0, 1, 3;
  0, 0, 2, 5;
  0, 0, 1, 7, 11;
  0, 0, 0, 3, 16, 21;
  0, 0, 0, 1, 12, 41, 43;
  0, 0, 0, 0,  4, 34, 94,  85;
  0, 0, 0, 0,  1, 18, 99, 219, 171;
  0, 0, 0, 0,  0,  5, 60, 261, 492,  341;
  0, 0, 0, 0,  0,  1, 25, 195, 678, 1101, 683;
		

Crossrefs

Cf. A111006.

Formula

From Philippe Deléham: (Start)
G.f.: 1/(1-yx(1-x)-2x^2*y*2);
Number triangle T(n, k) = Sum_{j=0..2k-n} C(n-k+j, n-k)*C(j, 2k-n-j)*2^(2k-n-j);
T(n, k) = A073370(k, n-k); T(n, k) = T(n-1, k-1) + T(n-2, k-1) + 2*T(n-2, k-2). (End)

A117316 Riordan array ((1-x)/(1-x-2x^2),x(1-x)/(1-x-2x^2)).

Original entry on oeis.org

1, 0, 1, 2, 0, 1, 2, 4, 0, 1, 6, 4, 6, 0, 1, 10, 16, 6, 8, 0, 1, 22, 28, 30, 8, 10, 0, 1, 42, 72, 54, 48, 10, 12, 0, 1, 86, 148, 158, 88, 70, 12, 14, 0, 1, 170, 336, 342, 288, 130, 96, 14, 16, 0, 1, 342, 716, 846, 648, 470, 180, 126, 16, 18, 0, 1
Offset: 0

Views

Author

Paul Barry, Mar 07 2006

Keywords

Comments

Product of A007318 and alternating sign version of A073370. Row sums are A001333. Diagonal sums are A052973. First column is A078008. Convolution array for A078008.

Examples

			Triangle begins
1,
0, 1,
2, 0, 1,
2, 4, 0, 1,
6, 4, 6, 0, 1,
10, 16, 6, 8, 0, 1,
22, 28, 30, 8, 10, 0, 1,
42, 72, 54, 48, 10, 12, 0, 1
		

Formula

T(n,k)=sum{j=0..n-k,sum{i=0..k+1, C(k+1,i)C(k+j,j)C(n-i-j,n-k-i-j)(-1)^(i+j)2^(n-k-i-j)}}
T(n,k)=T(n-1,k)+T(n-1,k-1)+2*T(n-2,k)-T(n-2,k-1), T(0,0)= 1, T(1,0)=0, T(1,1)=1, T(n,k)=0 if k<0 or if k>n. - Philippe Deléham, Jan 04 2013

A179533 Expansion of (1/(1-x-2x^2))*c(x/(1-x-2x^2)), c(x) the g.f. of A000108.

Original entry on oeis.org

1, 2, 7, 23, 85, 332, 1369, 5870, 25945, 117374, 540805, 2528675, 11966923, 57206972, 275824159, 1339721519, 6549093013, 32195473406, 159065828029, 789395034701, 3933239089903, 19668745466636, 98679891233803, 496570499905832, 2505670304785615, 12675395921692394, 64270076976110203, 326580624341708693, 1662796531746045157, 8481930651824392268, 43341418581113085697
Offset: 0

Views

Author

Paul Barry, Jan 08 2011

Keywords

Comments

Hankel transform is A168495(n+1).

Crossrefs

Programs

  • Maple
    with(LREtools): with(FormalPowerSeries): # requires Maple 2022
    ogf:= (1/(1-x-2*x^2))*(1 - sqrt(1 - 4*(x/(1-x-2*x^2)))) / (2*(x/(1-x-2*x^2))):
    init:= [1, 2, 7, 23, 85, 332, 1369];
    iseq:= seq(u(i-1)=init[i],i=1..nops(init)): req:= FindRE(ogf,x,u(n));
    rmin:= subs(n=n-4,MinimalRecurrence(req,u(n),{iseq})[1]); # Mathar's recurrence
    a:= gfun:-rectoproc({rmin, iseq}, u(n), remember):
    seq(a(n),n=0..30); # Georg Fischer, Nov 04 2022

Formula

G.f.: 1/(1-x-2x^2-x/(1-x/(1-x-2x^2-x/(1-x/(1-x-2x^2-x/(1-x/(1-x-2x^2-x/(1-x/(1-... (continued fraction);
a(n) = Sum_{k=0..n} A000108(k)*Sum_{j=0..n-k} C(k+j,k)*C(j,n-k-j)*2^(n-k-j).
a(n) = Sum_{k=0..n} A073370(n,k)*A000108(k).
D-finite with recurrence: (n+1)*a(n) +2*(1-3n)*a(n-1) +(n-1)*a(n-2) +4*(3n-5)*a(n-3) +4*(n-3)*a(n-4)= 0. - R. J. Mathar, Nov 17 2011
Previous Showing 11-18 of 18 results.