12078908

Appears in sequences

• a(n) = floor(Fibonacci(n)/2).at n=37A004695
• a(n) = C(n-1,1) + C(n-3,3) + ... + C(n-2*m-1,2*m+1), where m = floor((n-2)/4).at n=34A024490
• a(n) = (F(3*n+1) - 1)/2, where F=A000045 (the Fibonacci sequence).at n=12A049651
• First member of the Diophantine pair (m,k) that satisfies 5*(m^2 + m) = k^2 + k; a(n) = m.at n=12A077259
• Expansion of (1+x)/((1+x+x^2)(1-x-x^2)).at n=35A093040
• Row sums of triangle A099510, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + 2*z + z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.at n=17A099511
• A transform of (1-x)/(1-2x).at n=34A099517
• Define a(1)=0, a(2)=2 then a(n) = 3*a(n-1) - a(n-2), a(n+1) = 3*a(n)-a(n-1) and a(n+2) = 3*a(n+1) - a(n) + 2.at n=17A105073
• Expansion of g.f. (1+x)^2/((1 + x + x^2)*(1 + x - x^2)).at n=38A106511
• Number of different possible rows (or columns) in an n X n crossword puzzle.at n=34A130578
• a(n) = ((F(n-1)+F(n-2))-1)/2 if F(n) is odd, otherwise a(n) = ((F(n-1)+F(n-2))-2)/2, where F(n) = A000045(n) is the n-th Fibonacci number.at n=36A201864
• x-values in the solutions to x^2 + x = 5*y^2 + y.at n=6A257939
• a(n) = a(n-1) + a(n-2) - a(n-3) + a(n-4) for n > 4, where a(n)=0 for n < 4 and a(4) = 1.at n=39A293014
• a(n) is the integer k that minimizes |k/Fibonacci(n) - 1/2|.at n=37A293505