LOG-CONCAVITY OF ROWS OF PASCAL TYPE TRIANGLES
: Foldes Stephan, Major László
Publisher: UTIL MATH PUBL INC
: 2020
: Utilitas Mathematica
: UTILITAS MATHEMATICA
: UTILITAS MATHEMATICA
: 116
: 203
: 210
: 8
: 0315-3681
: http://www.combinatorialmath.ca/Utilitas/(external)
Menon's proof of the preservation of log-concavity of sequences under convolution becomes simpler when adapted to 2-sided infinite sequences. Under assumption of log-concavity of two 2-sided infinite sequences, the existence of the convolution is characterised by a convergence criterion. Preservation of log-concavity under convolution yields another method of establishing the log-concavity of rows of certain Pascal type triangles. This includes in particular the log-concavity of rows of a weighted Delannoy triangle. The method is also compared with known techniques of proving log-concavity.