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.

Showing 1-6 of 6 results.

A081104 Duplicate of A079028.

Original entry on oeis.org

1, 5, 24, 112, 512, 2304, 10240, 45056, 196608, 851968, 3670016, 15728640
Offset: 1

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Author

Keywords

A081106 6th binomial transform of (1,1,0,0,0,0,...).

Original entry on oeis.org

1, 7, 48, 324, 2160, 14256, 93312, 606528, 3919104, 25194240, 161243136, 1027924992, 6530347008, 41358864384, 261213880320, 1645647446016, 10344069660672, 64885527871488, 406239826673664, 2538998916710400, 15843353240272896, 98716277881700352, 614234617930579968
Offset: 0

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Author

Paul Barry, Mar 07 2003

Keywords

Comments

Main diagonal of array defined by m(1,j) = j; m(i,1) = i and m(i,j) = m(i-1,j) + 5*m(i-1,j-1). - Benoit Cloitre, Jun 13 2003

Crossrefs

Programs

  • Magma
    [(n+6)*6^(n-1): n in [0..25]]; // Vincenzo Librandi, Aug 06 2013
  • Mathematica
    CoefficientList[Series[(1 - 5 x)/(1 - 6 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
    LinearRecurrence[{12,-36},{1,7},30] (* Harvey P. Dale, Nov 07 2013 *)

Formula

a(n) = 12*a(n-1) - 36*a(n-2) with n > 1, a(0) = 1, a(1) = 7.
a(n) = (n + 6)*6^(n-1).
G.f.: (1 - 5*x)/(1 - 6*x)^2.
E.g.f.: exp(6*x)*(1 + x). - Stefano Spezia, Mar 05 2023

A082307 Expansion of e.g.f. (1+x)*exp(3*x)*cosh(x).

Original entry on oeis.org

1, 4, 16, 66, 280, 1208, 5248, 22816, 98944, 427392, 1838080, 7870976, 33568768, 142637056, 604045312, 2550276096, 10737713152, 45097779200, 188979871744, 790276734976, 3298540650496, 13743907405824, 57174629810176
Offset: 0

Views

Author

Paul Barry, Apr 09 2003

Keywords

Comments

Binomial transform of A002306; a(n)=(A082308(n)+A079028(n))/2

Crossrefs

Cf. A082308.

Programs

  • Magma
    m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!((1+x)*Exp(3*x)*Cosh(x))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Sep 16 2018
  • Mathematica
    With[{nmax = 50}, CoefficientList[Series[(1 + x)*Exp[3*x]*Cosh[x], {x, 0, nmax}], x]*Range[0, nmax]!] (* G. C. Greubel, Sep 16 2018 *)
  • PARI
    x='x+O('x^30); Vec(serlaplace((1+x)*exp(3*x)*cosh(x))) \\ G. C. Greubel, Sep 16 2018
    

Formula

a(n) = ((n+2)*2^(n-1) + (n+4)*4^(n-1))/2.
G.f.: ((1-3x)/(1-4x)^2 + (1-x)/(1-2x)^2)/2.
E.g.f. (1+x)*exp(3*x)*cosh(x).

A089944 Square array, read by antidiagonals, where the n-th row is the n-th binomial transform of the natural numbers, with T(0,k) = (k+1) for k>=0.

Original entry on oeis.org

1, 2, 1, 3, 3, 1, 4, 8, 4, 1, 5, 20, 15, 5, 1, 6, 48, 54, 24, 6, 1, 7, 112, 189, 112, 35, 7, 1, 8, 256, 648, 512, 200, 48, 8, 1, 9, 576, 2187, 2304, 1125, 324, 63, 9, 1, 10, 1280, 7290, 10240, 6250, 2160, 490, 80, 10, 1, 11, 2816, 24057, 45056, 34375, 14256, 3773, 704, 99, 11, 1
Offset: 0

Views

Author

Paul D. Hanna, Nov 23 2003

Keywords

Comments

The main diagonal is A089945: {T(n,n)=(2*n+1)*(n+1)^(n-1), n>=0}; the hyperbinomial transform of the main diagonal is the next lower diagonal in the array (A089946): {T(n+1,n) = 2*(n+1)*(n+2)^(n-1), n>=0}.

Examples

			Rows begin:
  {1, 2, 3, 4, 5, 6, 7,..},
  {1, 3, 8, 20, 48, 112, 256,..},
  {1, 4, 15, 54, 189, 648, 2187,..},
  {1, 5, 24, 112, 512, 2304, 10240,..},
  {1, 6, 35, 200, 1125, 6250, 34375,..},
  {1, 7, 48, 324, 2160, 14256, 93312,..},
  {1, 8, 63, 490, 3773, 28812, 218491,..},..
		

Crossrefs

Programs

  • Mathematica
    A089944[n_, k_] := (k + n + 1)*(n + 1)^(k - 1);
    Table[A089944[k, n - k], {n, 0, 10}, {k, 0, n}] (* Paolo Xausa, Jan 13 2025 *)
  • PARI
    T(n,k)=if(n<0 || k<0,0,(k+n+1)*(n+1)^(k-1))

Formula

T(n,k) = (k+n+1)*(n+1)^(k-1).
E.g.f.: (1+x)*exp(x)/(1-y*exp(x)).

A082309 Expansion of e.g.f.: (1+x)*exp(5*x)*cosh(x).

Original entry on oeis.org

1, 6, 36, 218, 1336, 8280, 51776, 325792, 2057856, 13023104, 82456576, 521826816, 3298727936, 20822038528, 131210919936, 825373859840, 5182772248576, 32487861092352, 203308891897856, 1270289732337664, 7924975155019776
Offset: 0

Views

Author

Paul Barry, Apr 09 2003

Keywords

Comments

Binomial transform of A082307.

Crossrefs

Programs

  • Magma
    m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!((1+x)*Exp(5*x)*Cosh(x))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Sep 16 2018
  • Mathematica
    With[{nn=30},CoefficientList[Series[(1+x)Exp[5x]Cosh[x],{x,0,nn}],x]Range[0,nn]!] (* or *) LinearRecurrence[{20,-148,480,-576},{1,6,36,218},30] (* Harvey P. Dale, Aug 27 2012 *)
  • PARI
    x='x+O('x^30); Vec(serlaplace((1+x)*exp(5*x)*cosh(x))) \\ G. C. Greubel, Sep 16 2018
    

Formula

a(n) = (A081106(n) + A079028(n))/2.
a(n) = ((n+4)*4^(n-1) + (n+6)*6^(n-1))/2.
G.f.: ((1-5*x)/(1-6*x)^2 + (1-3*x)/(1-4*x)^2)/2.
From Harvey P. Dale, Aug 27 2012: (Start)
E.g.f.: (1+x)*exp(5*x)*cosh(x).
a(n) = 20*a(n-1) - 148*a(n-2) + 480*a(n-3) - 576*a(n-4), n>3. (End)

Extensions

Definition clarified by Harvey P. Dale, Aug 27 2012

A235113 Irregular triangle read by rows: T(n,k) = number of independent vertex subsets of size k of the graph g_n obtained by attaching two pendant edges to each vertex of the complete graph K_n (0 <= k <= 2n).

Original entry on oeis.org

1, 1, 3, 1, 1, 6, 10, 6, 1, 1, 9, 27, 38, 27, 9, 1, 1, 12, 52, 116, 150, 116, 52, 12, 1, 1, 15, 85, 260, 490, 602, 490, 260, 85, 15, 1, 1, 18, 126, 490, 1215, 2052, 2436, 2052, 1215, 490, 126, 18, 1, 1, 21, 175, 826, 2541, 5467, 8547, 9900, 8547, 5467, 2541, 826, 175, 21, 1
Offset: 0

Views

Author

Emeric Deutsch, Jan 13 2014

Keywords

Comments

Sum of entries in row n = 2^{2n-4}*(4 + n) = A079028(n).
In the Maple program P[n] gives the independence polynomial of the graph g_n.

Examples

			Row 1 is 1,3,1; indeed, K_1 is the one-vertex graph and after attaching two pendant vertices we obtain the path graph ABC; the independent vertex subsets are: empty, {A}, {B}, {C}, and {A, C}.
Triangle begins:
1;
1,3,1;
1,6,10,6,1;
1,9,27,38,27,9,1;
1,12,52,116,150,116,52,12,1;
		

Crossrefs

Programs

  • Maple
    G := (1-z-x*z-x^2*z)/(1-z-2*x*z-x^2*z)^2: Gser := simplify(series(G, z = 0, 10)): for n from 0 to 9 do P[n] := sort(coeff(Gser, z, n)) end do: for n from 0 to 9 do seq(coeff(P[n], x, i), i = 0 .. 2*n) end do;# yields sequence in triangular form

Formula

Generating polynomial of row n (n>=0) is (1+x)^{2n-2}*((1+x)^2 + nx) (it is palindromic).
Bivariate generating polynomial: G(x,z) = (1-z-xz-x^2*z)/(1-z-2xz-x^2*z)^2.
G(1/x, x^2*z) = G(x,z) (this implies the above mentioned palindromicity).
Showing 1-6 of 6 results.