A101900 Column 0 of triangular matrix A101897, in which column k equals column 0 of A101897^(k+1) and where the n-th row sums are zero for n>0.

1, -1, 1, -2, 5, -17, 71, -357, 2101, -14203, 108609, -927961, 8769087, -90874197, 1025292311, -12516360103, 164433702745, -2313858448075, 34730232119381, -553983478001961, 9359820238735507, -167004393073794933, 3138414712193291915, -61966152586833353847

Offset: 0

Author

Paul D. Hanna, Dec 20 2004

Keywords

• sign

Comments

|a(n)| is the number of n-length permutations avoiding the dotted pattern 23\dot{1}(conjectured). - Michael D. Weiner, Jul 26 2018

Links

• Isak Hilmarsson, Ingibjorg Jonsdottir, Steinunn Sigurdardottir and Sigridur Vidarsdottir, Wilf-classification of mesh patterns of short length, Reykjavík University, Thesis, May 2011.
• Isak Hilmarsson, Ingibjorg Jonsdottir, Steinunn Sigurdardottir and Sigridur Vidarsdottir, Wilf-classification of mesh patterns of short length, The Electronic Journal of Combinatorics, Volume 22, Issue 4 (2015).

Crossrefs

Cf. A101897, A101898, A101899, A101901.