42118

Appears in sequences

• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 603", based on the 5-celled von Neumann neighborhood.at n=33A273173
• Consider constructing binary words that begin with 0 such that the subword 00, whenever it appears, is followed by 111. Then a(n) counts such words at length n (including those where the string 111 is yet being completed - see Example).at n=20A340215
• a(n) = floor(b(n)), where b(1) = 1 and b(n) = b(n-1) + Sum_{k=1..n-1} b(k)/(n-1).at n=44A376995