A373755 a(n) = A205497(n, floor((n - 1) / 2)). The middle coefficients of the Eulerian zig-zag polynomials.

1, 1, 1, 1, 3, 7, 31, 109, 623, 2951, 20641, 123216, 1019051, 7349140, 70148989, 593513485, 6421463423, 62382094567, 754405836811, 8277393686747, 110644077164479, 1353422057172923, 19814920352425441, 267391099520321166, 4255291684449288503, 62800765220575811118

Offset

0,5

Links

Table of n, a(n) for n=0..25.

T. Kyle Petersen and Yan Zhuang, Zig-zag Eulerian polynomials, arXiv:2403.07181 [math.CO], 2024.

Maple

1, 1, 1, seq(A205497row(n)[iquo(n, 2)], n = 3..25);

Crossrefs

Cf. A205497, A373754.

Sequence in context: A132153 A002357 A173062 * A306831 A105765 A061095

Adjacent sequences: A373752 A373753 A373754 * A373756 A373757 A373758

Keyword

nonn

Author

Peter Luschny, Jun 16 2024

Status

approved