28632

Appears in sequences

• a(n) = b(n) - c(n) where b(n) is the n-th Fibonacci number greater than 2 and c(n) is the n-th number not in sequence b( ).at n=19A014251
• a(n) = Sum_{k=0..floor(n/2)} T(n,k), T given by A026758.at n=14A026766
• Engel expansion of Pi^2/6, or zeta(2) = 1.64493.at n=11A059186
• Number of nonisomorphic semigroups of order n minus number of groups of order n.at n=5A186117
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 553", based on the 5-celled von Neumann neighborhood.at n=30A272848
• a(n) = a(n-1) + 3*a(n-2) - 3*a(n-3) - 2*a(n-4) + 2*a(n-5) for n >= 6, a(0) = 2, a(1) = 4, a(2) = 7, a(3) = 11, a(4) = 18, a(5) = 28.at n=24A289131