OFFSET
0,2
LINKS
Ariel Halpert, Flórián Lengyel and János Pach, Cellular telephone networks and random maps in hypergraphs, Discrete Appl. Math. 103 (2000), no. 1-3, 111-126.
FORMULA
a(n) = T(n, n) where T(1, n) = n, T(2, n) = n^2, and T(m, n) = T(m, n-1) + 2*m*T(m-1, n-1) - m*T(m-1, n-2) - binomial(m, 2)*T(m-2, n-2) for 1 <= m <= n+1. - Sean A. Irvine, Feb 03 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Florian Lengyel (flengyel(AT)email.gc.cuny.edu)
EXTENSIONS
More terms from Sean A. Irvine, Feb 03 2020
STATUS
approved