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.

A298213 Triangle read by rows, expansion of exp(x*exp(z)*tan(z)).

Original entry on oeis.org

1, 0, 1, 0, 2, 1, 0, 5, 6, 1, 0, 12, 32, 12, 1, 0, 41, 160, 110, 20, 1, 0, 142, 856, 900, 280, 30, 1, 0, 685, 4816, 7231, 3360, 595, 42, 1, 0, 3192, 29952, 58632, 37856, 9800, 1120, 56, 1, 0, 19921, 199680, 493100, 416640, 147126, 24192, 1932, 72, 1
Offset: 0

Views

Author

Peter Luschny, Jan 15 2018

Keywords

Examples

			Triangle starts:
0: 1;
1: 0,    1;
2: 0,    2,     1;
3: 0,    5,     6,     1;
4: 0,   12,    32,    12,     1;
5: 0,   41,   160,   110,    20,    1;
6: 0,  142,   856,   900,   280,   30,    1;
7: 0,  685,  4816,  7231,  3360,  595,   42,  1;
8: 0, 3192, 29952, 58632, 37856, 9800, 1120, 56, 1;
		

Crossrefs

T(n,1) = A009739(n), T(n,n) = A002378(n-1).
Row sums are A009248.
Cf. A075497.

Programs

  • Maple
    gf := exp(x*exp(z)*tan(z)):
    X := n -> series(gf, z, n+2):
    Z := n -> n!*expand(simplify(coeff(X(n), z, n))):
    A298213_row := n -> op(PolynomialTools:-CoefficientList(Z(n), x)):
    seq(A298213_row(n), n=0..8);