OFFSET
1,1
EXAMPLE
For n = 3, the strings 000, 010, 101, 111 have longest palindromic suffix of length 3; 001, 110 have longest palindromic suffix of length 1, and 011, 100 have longest palindromic suffix of length 2. So a(3) = 4*3 + 2*1 + 2*2 = 18.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Oct 10 2018
EXTENSIONS
a(21)-a(33) from Giovanni Resta, Oct 10 2018
STATUS
approved