OFFSET
1,1
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
FORMULA
a(n) is asymptotic to tau^(2-tau)*(2n)^(tau-1) and more precisely it seems that a(n) = round(tau^(2-tau)*(2n)^(tau-1)) +(-1, +0 or +1) where tau is the golden ratio.
EXAMPLE
Read 2,2,4,4,6,6,6,6,8,8,8,8,10,10,10,10,10,10 as (2,2),(4,4),(6,6,6,6),(8,8,8,8),(10,10,10,10,10,10) count occurrences between 2 parentheses, gives 2,2,4,4,6,... which is the sequence itself.
MATHEMATICA
a = {2, 2}; Do[a = Join[a, Array[2i&, a[[i]]]], {i, 2, 13}]; a (* Ivan Neretin, Apr 03 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 25 2003
STATUS
approved