OFFSET
1,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..50
J. D. Horton and A. Kurn, Counting sequences with complete increasing subsequences, Congressus Numerantium, 33 (1981), 75-80. MR 681905
FORMULA
a(n) ~ 9^(9*n + 1/2) / (2*Pi*n)^4. - Vaclav Kotesovec, Mar 03 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 14 2016
STATUS
approved