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.

A365593 Number of n X n Boolean relation matrices such that every block of its Frobenius normal form is either a 0 block or a 1 block.

Original entry on oeis.org

1, 2, 13, 219, 9322, 982243, 249233239, 148346645212, 202688186994599, 624913864623500599, 4289324010827093793808, 64841661094150427710360745, 2140002760057211517052090865983, 153082134018816602622335941790247946, 23590554099141037133024176892280338280237
Offset: 0

Views

Author

Geoffrey Critzer, Sep 10 2023

Keywords

Comments

A 1(0) block is such that every entry in the block is 1(0). If a Boolean relation matrix R is limit dominating then it must be that every block of R is either a 0 block or a 1 block. See Theorem 1.2 in Gregory, Kirkland, and Pullman.
Conjecture: lim_n->inf a(n)/(A003024(n)*2^n) = 1. In other words, almost all of the relations counted by this sequence have n strongly connected components. - Geoffrey Critzer, Sep 30 2023

Crossrefs

Programs

  • Mathematica
    nn = 12; d[x_] :=Total[Cases[Import["https://oeis.org/A003024/b003024.txt",
          "Table"], {, }][[All, 2]]*Table[x^(i - 1)/(i - 1)!, {i, 1, 41}]];
    Range[0, nn]! CoefficientList[Series[d[Exp[x] - 1 + x], {x, 0, nn}],x]

Formula

E.g.f.: D(exp(x)-1+x) where D(x) is the e.g.f. for A003024.