OFFSET
0,4
COMMENTS
a(2n-1) is positive and odd.
a(2n+1) - a(2n-1) is always either 0 or 2.
The number of repetitions of the value 2n-1 is A272729(n).
LINKS
Ivan Neretin, Table of n, a(n) for n = 0..8191
FORMULA
a(2n)=0.
a(2n-1)=A272728(n)+n.
EXAMPLE
A one-element series [0] coincides with its own reverse, hence a(1)=1.
[0,1] and [1,0] differ in every term, hence a(2)=0.
[0,1,0] is its own reverse, hence a(3)=3.
[0,1,0,3] and [3,0,1,0] differ in every term, hence a(4)=0.
[0,1,0,3,0] and [0,3,0,1,0] coincide in three terms, hence a(5)=3.
MATHEMATICA
Nest[Append[#, Count[# - Reverse[#], x_ /; x == 0]] &, {0}, 81]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ivan Neretin, May 05 2016
STATUS
approved