805306367

Appears in sequences

• a(0) = 1; a(n) = 3*2^n - 1, for n > 0.at n=28A052940
• a(0) = 0; for n > 0, a(n) = 3*2^(n-1) - 1.at n=29A055010
• Smallest number x > 1 such that phi(x) + sigma(x) = k*d(x)^n, i.e., the left-hand side is divisible by the n-th power of the number of divisors.at n=13A055470
• a(0) = 1; for n > 0, a(n) = 3*2^(n-1) - 1.at n=29A083329
• Numbers of the form 3*2^(p - 1) - 1 where p is prime.at n=9A097743
• Expansion of g.f.: (3+x+2*x^2-2*x^3)/((1-2*x)*(1+x^2)).at n=28A100720
• Smallest semiprime with Hamming weight n (i.e., smallest semiprime with exactly n ones when written in binary), or -1 if no such number exists.at n=28A102029
• a(n) = 3*2^n - 1.at n=28A153893
• a(n) = (n-1)*2^n - 1.at n=24A163383
• Numbers of the form i*4^j-1 (i=1..3, j >= 0).at n=44A180516
• a(n) = 3*4^n-1.at n=14A198693
• a(n) = 6*8^n-1.at n=9A198854
• a(n) = a(n-1) + 2*a(n-2) with n>1, a(0)=2, a(1)=7.at n=28A201630
• Independence number of the n-Mycielski graph.at n=30A266550
• Decimal representation of the n-th iteration of the "Rule 185" elementary cellular automaton starting with a single ON (black) cell.at n=15A267614
• 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 3", based on the 5-celled von Neumann neighborhood.at n=29A277867
• 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 51", based on the 5-celled von Neumann neighborhood.at n=29A278595
• 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 705", based on the 5-celled von Neumann neighborhood.at n=29A283651
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 813", based on the 5-celled von Neumann neighborhood.at n=29A284181
• 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 899", based on the 5-celled von Neumann neighborhood.at n=29A284354