A369026 a(n) = floor(n^(n - 1) / 2) for n > 0 and otherwise 0.

0, 0, 1, 4, 32, 312, 3888, 58824, 1048576, 21523360, 500000000, 12968712300, 371504185344, 11649042561240, 396857386627072, 14596463012695312, 576460752303423488, 24330595937833434240, 1092955779869348265984

Offset: 0

Author

Peter Luschny, Jan 12 2024

Keywords

• nonn

Crossrefs

Cf. A000169, A369025, A369027.

Programs

Mathematica

A369026[n_] := If[n > 0, Floor[n^(n-1) / 2], 0];
Array[A369026, 30, 0] (* Paolo Xausa, Jan 12 2024 *)

SageMath

def A369026(n): return n^(n - 1) // 2 if n > 0 else 0
print([A369026(n) for n in range(22)])