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.

A346384 Triangle read by rows. T(n,k) is the number of invertible n X n matrices over GF(3) such that the dimension of the eigenspace corresponding to the eigenvalue 1 is k, 0 <= k <= n, n >= 0.

Original entry on oeis.org

1, 1, 1, 27, 20, 1, 6291, 4719, 221, 1, 13589289, 10191960, 477750, 2120, 1, 266377183929, 199782888129, 9364822830, 41559870, 19481, 1, 47123189360124723, 35342392020078780, 1656674625945339, 7352106327720, 3446299857, 176540, 1
Offset: 0

Views

Author

Geoffrey Critzer, Jul 14 2021

Keywords

Examples

			             1;
             1,            1;
            27,           20,          1;
          6291,         4719,        221,        1;
      13589289,     10191960,     477750,     2120,     1;
  266377183929, 199782888129, 9364822830, 41559870, 19481, 1;
		

Crossrefs

Cf. A051680 (column k=0), A053290 (row sums).

Programs

  • Mathematica
    nn = 6; q = 3; b[p_, i_] := Count[p, i]; d[p_, i_] :=  Sum[j b[p, j], {j, 1, i}] + i Sum[b[p, j], {j, i + 1, Total[p]}]; aut[deg_, p_] :=  Product[Product[
       q^(d[p, i] deg) - q^((d[p, i] - k) deg), {k, 1, b[p, i]}], {i, 1, Total[p]}]; A027376 = Table[1/n Sum[MoebiusMu[n/d] q^d, {d, Divisors[n]}], {n, 1, nn}];
    g[u_, v_] := Total[Map[v^Length[#] u^Total[#]/aut[1, #] &, Level[Table[IntegerPartitions[n], {n, 0, nn}], {2}]]]; Map[Select[#, # > 0 &] &, Table[Product[q^n - q^i, {i, 0, n - 1}], {n, 0,  nn}] CoefficientList[
        Series[(g[u, v] /. v -> 1)*g[u, v]* Product[Product[1/(1 - (u/q^r)^d), {r, 1, \[Infinity]}]^A027376[[d]], {d, 2, nn}], {u, 0, nn}], {u, v}]] // Grid