A000530 Let p(n, s, x) be predicate that number of occurrences of s's in x >= 2*n - the length of the longest sequence of s's in x. Then a(n)=#{x in {0,1}* | x ends in 0 and p(n,0,x) and (there is no prefix y of x such that p(n,0,y) or p(n,1,y))}.

1, 5, 28, 226, 2077, 20770, 222884, 2529541

Offset: 1

Author

Jonas Wallgren [ jwc(AT)ida.liu.se ]

Keywords

• nonn
• hard
• more

Comments

a(9)>=29995812 (probably equal to this value)

Extensions

a(7)-a(8) from Sean A. Irvine, Nov 14 2010