268402689
domain: N
Appears in sequences
- a(n) = (2^n - 1)^2.at n=13A060867
- Resultant of the polynomial x^n-1 and the Chebyshev polynomial of the second kind U_2(x).at n=13A085435
- Expansion of (1 + 2*x^2)/((1 + x)*(1 - 2*x)*(1 - 2*x^2)).at n=27A085903
- Smallest square k == 1 (mod some n-th power), k > 1.at n=14A088037
- Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=12A208556
- Gaussian norm of 1+(1+i)^n.at n=28A238187
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 5", based on the 5-celled von Neumann neighborhood.at n=13A270007
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 73", based on the 5-celled von Neumann neighborhood.at n=13A270088
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 89", based on the 5-celled von Neumann neighborhood.at n=13A270130
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 659", based on the 5-celled von Neumann neighborhood.at n=13A273385
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 913", based on the 5-celled von Neumann neighborhood.at n=13A273767
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 969", based on the 5-celled von Neumann neighborhood.at n=13A273848
- Number of holes in a sheet of paper when you fold it n times and cut off the four corners.at n=28A274230
- a(2n) = A060867(n+1), a(2n+1) = A092440(n+1).at n=26A276918
- a(n) = 9*J(n)^2 where J(n) are the Jacobsthal numbers A001045 with J(0) = 1.at n=14A323210
- Numbers of the form M_p^2(M^p+2)^2, where M_p is a Mersenne prime (A000668) and p is a Mersenne exponent (A000043). Also the first element of the spectral basis of A330817.at n=3A330819
- a(n) is the largest perfect power < 2^n.at n=25A357752
- a(n) is the largest square with n binary digits.at n=25A357754