A268841 Number of sequences with n copies each of 1,2,...,5 and longest increasing subsequence of length 5.

1, 11389, 50775091, 162588279629, 449363984934526, 1162145520205261219, 2931247600219365331976, 7370846583668954571029069, 18683332440278067962764855531, 47964531978782851644184417448714, 124871404619023570844557764310152386

Offset: 1

Author

Alois P. Heinz, Feb 14 2016

Keywords

• nonn

Links

• Vaclav Kotesovec and Alois P. Heinz, Table of n, a(n) for n = 1..150 (terms n=1..80 from Vaclav Kotesovec)
• J. D. Horton and A. Kurn, Counting sequences with complete increasing subsequences, Congressus Numerantium, 33 (1981), 75-80. MR 681905

Crossrefs

Column k=5 of A047909.

Formula

a(n) ~ 5^(5*n+1/2) / (2*Pi*n)^2. - Vaclav Kotesovec, Feb 21 2016