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.

A197420 Triangle with the denominator of the coefficient [x^k] of the second order Bernoulli polynomial B_n^(2)(x) in row n, column 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 6, 1, 1, 2, 2, 1, 1, 10, 1, 1, 1, 1, 6, 2, 1, 3, 1, 1, 42, 1, 2, 1, 2, 1, 1, 6, 6, 2, 2, 2, 2, 1, 1, 30, 3, 3, 3, 1, 1, 3, 1, 1, 10, 10, 1, 1, 1, 5, 1, 1, 1, 1, 22, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 6, 2, 2, 2, 1, 1, 1, 1, 2, 6, 1, 1, 2730, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1
Offset: 0

Views

Author

R. J. Mathar, Oct 14 2011

Keywords

Comments

Denominators of the polynomials defined in A197419.

Examples

			1;
1,1;
6,1,1;
2,2,1,1;
10,1,1,1,1;
6,2,1,3,1,1;
42,1,2,1,2,1,1;
6,6,2,2,2,2,1,1;
30,3,3,3,1,1,3,1,1;
10,10,1,1,1,5,1,1,1,1;
22,1,2,1,1,1,1,1,2,1,1;
6,2,2,2,1,1,1,1,2,6,1,1;
2730,1,1,1,2,1,1,1,2,1,1,1,1;
		

Programs

  • Mathematica
    t[n_, m_] := If [n == m, 1, 2*Binomial[n, m]*Sum[StirlingS2[n-m, k]*StirlingS1[2+k, 2]/((k+1)*(2+k)), {k, 1, n-m}]]; Table[t[n, m] // Denominator, {n, 0, 12}, {m, 0, n}] // Flatten (* Jean-François Alcover, Dec 12 2013, after Vladimir Kruchinin *)