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.

A297892 Triangle read by rows. T(n,k) is the number of n X n diagonalizable matrices over GF(3) that have rank k, 0 <= k <= n, n >= 0.

Original entry on oeis.org

1, 1, 2, 1, 24, 14, 1, 234, 1638, 236, 1, 2160, 147420, 254880, 12692, 1, 19602, 12349260, 208173240, 124394292, 1783784, 1, 176904, 1011404394, 157378969440, 916910326332, 157779262368, 811523288
Offset: 0

Views

Author

Geoffrey Critzer, Jan 07 2018

Keywords

Examples

			Triangle begins
  1;
  1,     2;
  1,    24,       14;
  1,   234,     1638,       236;
  1,  2160,   147420,    254880,     12692;
  1, 19602, 12349260, 208173240, 124394292, 1783784;
		

Crossrefs

Cf. A296548, A053846 (main diagonal), A290516 (row sums).

Programs

  • Mathematica
    nn = 5; g[n_] := (q - 1)^n  q^Binomial[n, 2] FunctionExpand[QFactorial[n, q]] /. q -> 3;G[n] := Sum[u z^r/g[r], {r, 0, nn}]; Grid[Map[Select[#, # > 0 &] &,Table[g[n], {n, 0, nn}] CoefficientList[Series[Sum[(u z)^r/g[r] , {r, 0, nn}]^2 Sum[
           z^r/g[r], {r, 0, nn}], {z, 0, nn}], {z, u}]]]

Formula

T(n,k)/A053290(n) is the coefficient of y^k*x^n in the expansion of Sum_{n>=0} x^n\A053290(n) * (Sum_{n>=0} y*x^n\A053290(n))^2.