28243

Appears in sequences

• a(n) = a(n-1) + Sum_{k=0..n-3} a(k) for n >= 2, a(0)=1, a(1)=2.at n=19A049853
• Expansion of (1+x^2)*(1+x^5)/( Product_{j=1..7} (1-x^j) ).at n=44A060962
• a(1) = 1, a(2) = 2, a(3) = 3, a(n+3) = a(n) + a(n+1).at n=35A084338
• Numbers n such that sigma_3(n) is divisible by square of cototient of n, while n is not a prime number.at n=16A091286
• Sum of all n-digit Padovan numbers.at n=3A130450
• Composite numbers k for which k - phi(k) divides k-1.at n=14A160599
• Numbers k such that 2^(k-1)+2*k-1 is a prime number.at n=15A192764
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 494", based on the 5-celled von Neumann neighborhood.at n=43A272548
• Antidiagonal sums of triangle A104684.at n=8A349713