536870904

Appears in sequences

• Number of ways of 4-coloring a map in which there is a central circle surrounded by an annulus divided into n-1 regions. There are n regions in all.at n=24A090860
• a(n) = Sum_{k=0..n} floor(C(n,k)/2).at n=30A120739
• a(n) = 8*(2^n - 1).at n=25A159741
• Row sums of triangle A166455.at n=28A166456
• a(n) = round((2^n - n - 1)/4).at n=30A173010
• Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 617", based on the 5-celled von Neumann neighborhood.at n=29A283350
• a(n) = 2^(n-1) - tau(n) where tau(n) is the number of divisors of n.at n=29A349094