839324

Appears in sequences

• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 33", based on the 5-celled von Neumann neighborhood.at n=9A269811
• a(n) = Sum_{k=1..n} C(n-k, floor((n-k)/k)).at n=24A273161