16769025

Appears in sequences

• a(n) = (2^n - 1)^2.at n=11A060867
• Resultant of the polynomial x^n-1 and the Chebyshev polynomial of the second kind U_2(x).at n=11A085435
• Expansion of (1 + 2*x^2)/((1 + x)*(1 - 2*x)*(1 - 2*x^2)).at n=23A085903
• Smallest square k == 1 (mod some n-th power), k > 1.at n=12A088037
• Smallest number having exactly n divisors of the form 8*k + 7.at n=31A188226
• 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=10A208556
• Hilltop maps: number of n X 3 binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..3 n X 3 array.at n=7A218237
• 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=11A270007
• 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=11A270088
• 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=11A270130
• 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=11A273385
• 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=11A273767
• 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=11A273848
• Number of holes in a sheet of paper when you fold it n times and cut off the four corners.at n=24A274230
• a(2n) = A060867(n+1), a(2n+1) = A092440(n+1).at n=22A276918
• Numbers a(n) = (T(b(n)))^2, where T(b(n)) is the triangular number of b(n)= A000217(b(n)) and b(n)=A006451(n). Also a(n) = parameters K of the Bachet Mordell equation y^2=x^3+K, where x= T(b(n)) = A006454(n) and y= T(b(n))* sqrt(T(b(n))+1) = A285955(n).at n=5A285985
• a(n) = 9*J(n)^2 where J(n) are the Jacobsthal numbers A001045 with J(0) = 1.at n=12A323210
• Smallest number having exactly n divisors of the form 8*k + 5.at n=34A343106
• a(n) is the smallest odd number that has n middle divisors.at n=10A354385
• a(n) is the largest perfect power < 2^n.at n=21A357752