A106592 Irregular triangle read by rows generated by the morphism 1->456, 2->44, 3->55, 4->22, 5->33, 6->123 starting from a(0)=1.

1, 4, 5, 6, 2, 2, 3, 3, 1, 2, 3, 4, 4, 4, 4, 5, 5, 5, 5, 4, 5, 6, 4, 4, 5, 5, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 1, 2, 3, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4, 5, 5, 5, 5, 4, 5, 6, 4, 4, 5, 5, 4

Offset

0,2

Links

Paolo Xausa, Table of n, a(n) for n = 0..8177 (rows 0..11 of triangle, flattened).

Curtis T. McMullen, Prym varieties and Teichmüller curves, Duke Math. J. 133(3) (2006), 569-590.

Example

Triangular begin:
  1;
  4, 5, 6;
  2, 2, 3, 3, 1, 2, 3;
  4, 4, 4, 4, 5, 5, 5, 5, 4, 5, 6, 4, 4, 5, 5;
  2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 1, 2, 3, 2, 2, 2, 2, 3, 3, 3, 3;
  ...

Mathematica

SubstitutionSystem[{1 -> {4, 5, 6}, 2 -> {4, 4}, 3 -> {5, 5}, 4 -> {2, 2}, 5 -> {3, 3}, 6 -> {1, 2, 3}}, {1}, 5] (* Paolo Xausa, May 11 2026 *)

Crossrefs

Cf. A106591.

Sequence in context: A076087 A082486 A106591 * A106593 A276036 A305006

Adjacent sequences: A106589 A106590 A106591 * A106593 A106594 A106595

Keyword

nonn,tabf,easy

Author

Roger L. Bagula, May 10 2005

Extensions

Edited by Sean A. Irvine, May 10 2026

Status

approved