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.

A212261 Array A(i,j) read by antidiagonals: A(i,j) is the (2i-1)-th derivative of sin(sin(sin(...sin(x)))) nested j times evaluated at 0.

Original entry on oeis.org

1, 1, -1, 1, -2, 1, 1, -3, 12, -1, 1, -4, 33, -128, 1, 1, -5, 64, -731, 1872, -1, 1, -6, 105, -2160, 25857, -37600, 1, 1, -7, 156, -4765, 121600, -1311379, 990784, -1, 1, -8, 217, -8896, 368145, -10138880, 89060065, -32333824, 1
Offset: 1

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Author

John M. Campbell, May 12 2012

Keywords

Comments

The determinant of the n X n such matrix has a closed form given in the formula section (and the Mathematica code below).
Rows appear to be given by polynomials (see formula section).

Examples

			Evaluate the fifth derivative of sin(sin(sin(x))) at 0, which is 33. So the (3,3) entry of the array is 33. The array begins as:
|  1      1        1         1         1          1 |
| -1     -2       -3        -4        -5         -6 |
|  1     12       33        64       105        156 |
| -1   -128     -731     -2160     -4765      -8896 |
|  1   1872    25857    121600    368145     873936 |
| -1 -37600 -1311379 -10138880 -42807605 -130426016 |
		

Crossrefs

Programs

  • Maple
    A:= (i, j)-> (D@@(2*i-1))(sin@@j)(0):
    seq(seq(A(i, 1+d-i), i=1..d), d=1..9); # Alois P. Heinz, May 14 2012
  • Mathematica
    A[a_, b_] :=
      A[a, b] =
       Array[D[Nest[Sin, x, #2], {x, 2*#1 - 1}] /. x -> 0 &, {a, b}];
    Print[A[7, 7] // MatrixForm];
    Table2 = {};
    k = 1;
    While[k < 8, Table1 = {};
      i = 1;
      j = k;
      While[0 < j,
       AppendTo[Table1, First[Take[First[Take[A[7, 7], {i, i}]], {j, j}]]];
       j = j - 1;
       i = i + 1];
      AppendTo[Table2, Table1];
      k++];
    Print[Flatten[Table2]]
    Print[Table[Det[A[n, n]], {n, 1, 7}]];
    Print[Table[(
      I^(n + n^2) 2^(-(1/12) + n^2) 3^(n/2 - n^2/2)
        Glaisher^3 (-(1/\[Pi]))^
       n BarnesG[1/2 + n] BarnesG[1 + n] BarnesG[3/2 + n])/E^(1/4), {n, 1, 7}]]

Formula

A(i,j) = ((d/dx)^(2i-1) sin^j(x))_{x=0}.
Let A_n denote the n X n such matrix. Then:
det(A_n)=(i^(n + n^2) 2^(-(1/12) + n^2) 3^(n/2 - n^2/2) G^3 (-(1/pi))^n B(1/2 + n) B(1 + n) B(3/2 + n))/e^(1/4), where B is the Barnes G-function and G is the Glaisher-Kinkelin constant (and i is the imaginary unit). (This can be shown by evaluating recurrence relations for det(A_n)). See Mathematica code below.
First row: 1.
Second row: -x.
Third row: x (5 x - 4).
Fourth row: -(1/3) x (164 + 7 x (-48 + 25 x)).
Fifth row: (8 - 7 x)^2 x (-24 + 25 x).
Sixth row: -(1/3) x (213568 - 766656 x + 1004696 x^2 - 572880 x^3 + 121275 x^4).
Seventh row: 1/3 x (-14371328 + 65012064 x - 111160192 x^2 + 91291200 x^3 - 36552516 x^4 + 5780775 x^5).
Second column: A003712.
Third column: A003715.