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.

A293486 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. Product_{i>0} Sum_{j=0..k} x^(j*(2*i-1))/j!.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 6, 0, 1, 1, 1, 6, 24, 0, 1, 1, 1, 7, 24, 120, 0, 1, 1, 1, 7, 24, 180, 720, 0, 1, 1, 1, 7, 25, 180, 1080, 5040, 0, 1, 1, 1, 7, 25, 180, 1200, 10080, 80640, 0, 1, 1, 1, 7, 25, 181, 1200, 10080, 90720, 725760, 0, 1, 1, 1, 7, 25
Offset: 0

Views

Author

Seiichi Manyama, Oct 10 2017

Keywords

Examples

			Square array begins:
   1,   1,   1,   1,   1, ...
   0,   1,   1,   1,   1, ...
   0,   0,   1,   1,   1, ...
   0,   6,   6,   7,   7, ...
   0,  24,  24,  24,  25, ...
   0, 120, 180, 180, 180, ...
		

Crossrefs

Columns k=0..3 give A000007, A293487, A293488, A293489.
Rows n=0 gives A000012.
Main diagonal gives A088009.
Cf. A293135.

A293463 Expansion of Product_{m>0} (1 + x^(2*m-1) + 2*x^(4*m-2) + 3*x^(6*m-3)).

Original entry on oeis.org

1, 1, 2, 4, 1, 3, 6, 5, 9, 13, 12, 17, 23, 22, 25, 30, 46, 53, 62, 74, 80, 106, 117, 135, 170, 183, 224, 267, 279, 325, 397, 444, 512, 610, 679, 791, 877, 989, 1157, 1298, 1476, 1669, 1909, 2134, 2390, 2721, 3012, 3391, 3887, 4308, 4808, 5460, 6018, 6752, 7552
Offset: 0

Views

Author

Seiichi Manyama, Oct 09 2017

Keywords

Crossrefs

Column k=3 of A293461.
Cf. A293489.

Programs

  • Mathematica
    nmax = 100; CoefficientList[Series[Product[(1 + x^(2*k-1) + 2*x^(4*k-2) + 3*x^(6*k-3)), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Oct 09 2017 *)
  • PARI
    m = 80; Vec(prod(k=1, m, 1 + x^(2*k-1) + 2*x^(4*k-2) + 3*x^(6*k-3)) + O(x^m)) \\ Michel Marcus, Oct 10 2017
Showing 1-2 of 2 results.