OFFSET
0,2
LINKS
John Cerkan,Table of n, a(n) for n = 0..3300
J.-M. Champarnaud and J.-E. Pin,A maxmin problem on finite automata,Discrete Appl. Math. 23 (1989), no. 1, 91-96.
FORMULA
a(n) = Sum_{k=0..n} min(2^k,2^(2^(n-k))-1). -Sean A. Irvine,Jun 24 2011
MAPLE
a:= n-> add((t-> `if`(t>k, 2^k, 2^t-1))(2^(n-k)), k=0..n):
seq(a(n), n=0..36); #Alois P. Heinz,Apr 13 2022
PROG
(PARI) a(n) = sum(k=0, n, min(2^k, 2^(2^(n-k))-1)) \\ (works while n<29)Michel Marcus,May 25 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(34)-a(36) fromSean A. Irvine,Jun 23 2011
STATUS
approved