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.

A182534 Array read by antidiagonals: coefficient of the Euler-Mascheroni constant in below expression.

Original entry on oeis.org

1, 1, 2, 2, 2, 3, 5, 4, 2, 6, 14, 10, 3, 4, 10, 42, 28, 6, 6, 5, 20, 132, 84, 14, 12, 6, 10, 35, 429, 264, 36, 28, 10, 12, 14, 70, 1430, 858, 99, 72, 20, 20, 14, 28, 126, 4862, 2860, 286, 198, 45, 40, 20, 28, 42, 252
Offset: 1

Views

Author

John M. Campbell, May 05 2012

Keywords

Comments

The (i,j)-entry of the array is the coefficient of the Euler-Mascheroni constant in: -2^(i+2j-1)/Pi*int(log(x)*cos(x)^i*sin(x)^(2j-1)/x, x=0..infinity); see Mathematica code below.
First row: A000108.
Second row: -A002420.
Third row: A007054.
Fourth row: A002421.
Fifth row: A007272.
Sixth row: -A002422.
Eighth row: A002423.
First column: A001405.
Second column: A089408.
Odd entries on main diagonal: A126596.

Examples

			Evaluate: -256/Pi*int(cos(x)^3*log(x)*sin(x)^5/x, x=0..infinity) = 3*eulergamma-log(9/8). Thus the (3,3) entry of the array is 3, the coefficient of the Euler-Mascheroni constant in this expression.
The array begins as:
| 1   1   2   5   14  42  132 429  ... |
| 2   2   4   10  28  84  264 858  ... |
| 3   2   3   6   14  36  99  286  ... |
| 6   4   6   12  28  72  198 572  ... |
| 10  5   6   10  20  45  110 286  ... |
| 20  10  12  20  40  90  220 572  ... |
| 35  14  14  20  35  70  154 364  ... |
| 70  28  28  40  70  140 308 728  ... |
| ... ... ... ... ... ... ... ...  ... |
		

Crossrefs

Programs

  • Mathematica
    A[a_, b_] :=
      A[a, b] =
       Array[Coefficient[
          Integrate[
            Log[x]*Cos[x]^#1*Sin[x]^(2 #2 - 1)/x, {x, 0,
             Infinity}] (2^(#1 + 2 #2 - 1))/(-\[Pi]), EulerGamma] &, {a, b}];
    A[11, 11];
    Print[A[11, 11] // MatrixForm];
    Table2 = {};
    k = 1;
    While[k < 11, Table1 = {};
      i = 1;
      j = k;
      While[0 < j,
        AppendTo[Table1,
        First[Take[First[Take[A[11, 11], {i, i}]], {j, j}]]];
        j = j - 1;
        i = i + 1];
        AppendTo[Table2, Table1];
        k++];
    Print[Flatten[Table2]]