OFFSET
1,2
COMMENTS
The next term, a(9), has 154 digits. - Harvey P. Dale, Apr 13 2012
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..11
Delbrin Ahmed, On subuniverses of lattices and semilattices, Ph. D. Thesis, Univ. of Szeged (Hungary, 2022).
MATHEMATICA
2^(2^Range[9]-2) (* Harvey P. Dale, Apr 13 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Matt Kasper (matt192837(AT)hotmail.com)
EXTENSIONS
a(8) from Harvey P. Dale, Apr 13 2012
STATUS
approved