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 1-2 of 2 results.

A176204 Triangle T(n, k) = 4 * A008292(n+1, k) - 3, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 13, 1, 1, 41, 41, 1, 1, 101, 261, 101, 1, 1, 225, 1205, 1205, 225, 1, 1, 477, 4761, 9661, 4761, 477, 1, 1, 985, 17169, 62473, 62473, 17169, 985, 1, 1, 2005, 58429, 352933, 624757, 352933, 58429, 2005, 1, 1, 4049, 191357, 1820765, 5241413, 5241413, 1820765, 191357, 4049, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 11 2010

Keywords

Comments

This sequence belongs to the class defined by T(n, m, q) = 2*T(n, m, q-1) - 1. The first few q values gives the sequences: A008292(n+1, k) (q=0), A176200 (q=1), this sequence (q=2).
Row sums are: {1, 2, 15, 84, 465, 2862, 20139, 161256, 1451493, 14515170, 159667167, ...}.
Former title: A recursive symmetrical triangular sequence based on Eulerian numbers: q=2: T(n, m, q) = 2*T(n, m, q-1) - 1.

Examples

			Triangle begins as:
  1;
  1,    1;
  1,   13,      1;
  1,   41,     41,       1;
  1,  101,    261,     101,       1;
  1,  225,   1205,    1205,     225,       1;
  1,  477,   4761,    9661,    4761,     477,       1;
  1,  985,  17169,   62473,   62473,   17169,     985,      1;
  1, 2005,  58429,  352933,  624757,  352933,   58429,   2005,    1;
  1, 4049, 191357, 1820765, 5241413, 5241413, 1820765, 191357, 4049, 1;
		

Crossrefs

Programs

  • Magma
    Eulerian:= func< n,k | (&+[(-1)^j*Binomial(n+1,j)*(k-j+1)^n: j in [0..k+1]]) >;
    [[4*Eulerian(n+1,k) -3: k in [0..n]]: n in [0..12]]; // G. C. Greubel, Mar 12 2020
    
  • Maple
    A008292:= (n,k) -> add((-1)^j*binomial(n+1,j)*(k-j+1)^n, j=0..k+1);
    A176204:= (n,k,q) -> 2^q*( A008292(n+1,k) -1) + 1;
    seq(seq( A176204(n,k,2), k=0..n), n=0..12); # G. C. Greubel, Mar 12 2020
  • Mathematica
    Eulerian[n_, k_]:= Sum[(-1)^j*Binomial[n+1, j]*(k-j+1)^n, {j,0,k+1}];
    T[n_, m_, q_]:= 2^q*Eulerian[n+1, m] - 2^q +1;
    Table[T[n, m, 2], {n,0,12}, {m,0,n}]//Flatten (* modified by G. C. Greubel, Mar 12 2020 *)
  • PARI
    Eulerian(n,k) = sum(j=0,k+1, (-1)^j*binomial(n+1,j)*(k-j+1)^n);
    T(n,k,q) = 2^q*Eulerian(n+1,k) - (2^q - 1); \\ G. C. Greubel, Mar 12 2020
    
  • Sage
    def Eulerian(n,k): return sum((-1)^j*binomial(n+1,j)*(k-j+1)^n for j in (0..k+1))
    def T(n,k,q): return 2^q*Eulerian(n+1,k) - 2^q + 1
    [[T(n,k,2) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Mar 12 2020

Formula

T(n, m, q) = 2*T(n, m, q-1) - 1, with T(n, m, 0) = A008292(n+1, m).
From G. C. Greubel, Mar 12 2020: (Start)
T(n, k, q) = 2^q * A008292(n+1, k) - (2^q - 1).
Sum_{k=0..n} T(n, k, q) = (n+1)*( 2^q * n! - 2^q + 1) (row sums). (End)

Extensions

Edited by G. C. Greubel, Mar 12 2020

A174033 T(n, m) = Sum_{i=0..10} floor(Eulerian(n+1, m)/2^i).

Original entry on oeis.org

1, 1, 1, 1, 7, 1, 1, 19, 19, 1, 1, 49, 130, 49, 1, 1, 110, 599, 599, 110, 1, 1, 236, 2376, 4826, 2376, 236, 1, 1, 487, 8578, 31220, 31220, 8578, 487, 1, 1, 997, 29200, 176378, 312223, 176378, 29200, 997, 1, 1, 2018, 95630, 909937, 2619425, 2619425, 909937, 95630, 2018, 1
Offset: 0

Views

Author

Roger L. Bagula, Mar 06 2010

Keywords

Examples

			Triangle begins:
  {1},
  {1, 1},
  {1, 7, 1},
  {1, 19, 19, 1},
  {1, 49, 130, 49, 1},
  {1, 110, 599, 599, 110, 1},
  {1, 236, 2376, 4826, 2376, 236, 1},
  {1, 487, 8578, 31220, 31220, 8578, 487, 1},
  {1, 997, 29200, 176378, 312223, 176378, 29200, 997, 1},
  {1, 2018, 95630, 909937, 2619425, 2619425, 909937, 95630, 2018, 1},
  ...
		

Crossrefs

Programs

  • Mathematica
    << DiscreteMath`Combinatorica`
    Sum[Floor[Eulerian[n + 1, m]/2^i], {i, 0, 10}];
    Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}];
    Flatten[%]

Formula

T(n, m) = Sum_{i=0..10} floor(Eulerian(n+1, m)/2^i), where Eulerian(n, k) = A008292(n, k).
Showing 1-2 of 2 results.