A268840 Number of sequences with n copies each of 1,2,3,4 and longest increasing subsequence of length 4.

1, 641, 195709, 46922017, 10258694241, 2176464012941, 460827731023773, 98540942707986273, 21364658238692907265, 4697818999010952011441, 1046430770756355786405517, 235755137688345453796236397, 53640184515807269993604743389, 12308974812428409561104536925709

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..400

J. D. Horton and A. Kurn, Counting sequences with complete increasing subsequences, Congressus Numerantium, 33 (1981), 75-80. MR 681905

Vaclav Kotesovec, Recurrence (of order 4)

Formula

a(n) ~ 2^(8*n-1/2) / (Pi*n)^(3/2). - Vaclav Kotesovec, Feb 21 2016

Crossrefs

Column k=4 of A047909.

Sequence in context: A206164 A206378 A229851 * A230715 A135384 A253420

Adjacent sequences: A268837 A268838 A268839 * A268841 A268842 A268843

Keyword

nonn

Author

Alois P. Heinz, Feb 14 2016

Status

approved