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.

A128249 T(n,k) is the number of unlabeled acyclic single-source automata with n transient states on a (k+1)-letter input alphabet.

Original entry on oeis.org

1, 3, 1, 16, 7, 1, 127, 139, 15, 1, 1363, 5711, 1000, 31, 1, 18628, 408354, 189035, 6631, 63, 1, 311250, 45605881, 79278446, 5470431, 42196, 127, 1, 6173791, 7390305396, 63263422646, 12703473581, 147606627, 262459, 255, 1, 142190703, 1647470410551
Offset: 1

Views

Author

R. J. Mathar, May 09 2007

Keywords

Comments

Table with rows n=1,2,... and columns k=1,2,3,... is read along antidiagonals.

Crossrefs

Programs

  • Maple
    T := proc(n,k) local kn,A,i,j ; kn := k*n ; A := matrix(kn,kn) ; for i from 1 to kn do for j from 1 to kn do A[i,j] := abs(combinat[stirling1](floor((i-1)/k)+2,floor((i-1)/k)+1+i-j)) ; od ; od ; linalg[det](A) ; end: for d from 1 to 9 do for n from d to 1 by -1 do k := d+1-n ; printf("%d, ",T(n,k)) ; od ; od;
  • Mathematica
    t[n_, k_] := Module[{kn, a, i, j}, kn = k*n; For[i = 1, i <= kn, i++, For[j = 1, j <= kn, j++, a[i, j] = Abs[StirlingS1[Floor[(i-1)/k]+2, Max[0, Floor[(i-1)/k]+1+i-j]]]]]; Det[Array[a, {kn, kn}]]]; Table[t[n-k, k], {n, 1, 10}, {k, 1, n-1}] // Flatten (* Jean-François Alcover, Jan 10 2014, translated from Maple *)