A395500 Number of derangements of [2*n] with n ascents.

1, 0, 4, 104, 5544, 470504, 58753904, 10156209720, 2324260081504, 680646923248160, 248326954072946112, 110464702295866844144, 58859196480283762242456, 37012431669369905733825528, 27123742582714531037238248464, 22914844643767718841136166514808

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..225

Formula

a(n) = A219836(2*n,n-1) for n > 0.

a(n) ~ sqrt(3) * 2^(2*n+1) * n^(2*n) / exp(2*n+1). - Vaclav Kotesovec, Apr 29 2026

Crossrefs

Central coefficients of the A395497 triangle.

Cf. A219836, A395488.

Sequence in context: A356213 A303135 A326284 * A302733 A098696 A013054

Adjacent sequences: A395497 A395498 A395499 * A395501 A395502 A395503

Keyword

nonn

Author

Seiichi Manyama, Apr 25 2026

Status

approved