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.

A117398 Matrix log of triangle A117396.

Original entry on oeis.org

0, 1, 0, 0, 2, 0, -1, 2, 3, 0, -3, 4, 5, 4, 0, -9, 14, 15, 9, 5, 0, -33, 68, 65, 34, 14, 6, 0, -153, 404, 359, 174, 63, 20, 7, 0, -873, 2804, 2375, 1098, 371, 104, 27, 8, 0, -5913, 22244, 18215, 8154, 2639, 692, 159, 35, 9, 0, -46233, 198644, 158615, 69354, 21791, 5480, 1179, 230, 44, 10, 0
Offset: 0

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Author

Paul D. Hanna, Mar 11 2006

Keywords

Comments

Column 0 contains negative of sequence A007489.

Examples

			Triangle begins:
      0;
      1,     0;
      0,     2,     0;
     -1,     2,     3,    0;
     -3,     4,     5,    4,    0;
     -9,    14,    15,    9,    5,   0;
    -33,    68,    65,   34,   14,   6,   0;
   -153,   404,   359,  174,   63,  20,   7,  0;
   -873,  2804,  2375, 1098,  371, 104,  27,  8,  0;
  -5913, 22244, 18215, 8154, 2639, 692, 159, 35,  9,  0;
		

Crossrefs

Cf. A117396, A007489 (column 0), A117399 (column 1).

Programs

  • Mathematica
    m=12;
    M= Table[If[k>n-1, 0, If[k==n-1, n, -1]], {n,0,m+1}, {k,0,m+1}];
    T:= T= Sum[MatrixPower[M, j]/j, {j,m+1}];
    Table[T[[n+1, k+1]], {n,0,m}, {k,0,n}]//Flatten (* G. C. Greubel, Sep 06 2022 *)
  • PARI
    {T(n,k)=local(M=matrix(n+4,n+4,r,c,if(r>=c,if(r==c+1,-c,1))), L=sum(m=1,n+4,(M^0-M)^m/m));L[n+1,k+1]}

Formula

From G. C. Greubel, Sep 06 2022: (Start)
T(n, n) = 0.
T(n, n-1) = A000027(n).
T(n, n-2) = A000096(n-2).
T(n, 0) = n*[n<2] - A007489(n-2)*[n>1].
T(n, 1) = 0 + 2*A117399(n-1)*[n>1].
Sum_{k=0..n} T(n, k) = A003422(n). (End)