OFFSET
1,2
COMMENTS
a(n) is the number of relations on a set with n elements that are not functions.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..57
Mohammad K. Azarian, Remarks and Conjectures Regarding Combinatorics of Discrete Partial Functions, Int'l Math. Forum (2022) Vol. 17, No. 3, 129-141.
EXAMPLE
a(1) = 2^(1^2) - 1^1 = 1.
a(2) = 2^(2^2) - 2^2 = 12.
a(3) = 2^(3^2) - 3^3 = 485.
MATHEMATICA
Table[2^(n^2) - n^n, {n, 12}] // Flatten
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, May 14 2021
STATUS
approved