567451585

Appears in sequences

• Denominators of continued fraction convergents to sqrt(5).at n=15A001076
• a(n) = Fibonacci(6*n + 3)/2.at n=7A007805
• Denominators of continued fraction convergents to sqrt(20).at n=14A041031
• Denominators of continued fraction convergents to sqrt(45).at n=22A041077
• Denominators of continued fraction convergents to sqrt(80).at n=14A041143
• Expansion of x*(1 + x - 2*x^2) / ( 1 - 4*x^2 - x^4).at n=30A059973
• Nonprimes which are the average of two consecutive Fibonacci numbers.at n=13A071683
• a(1)=1; for n > 2, a(n) is the smallest integer > a(n-1) such that frac(sqrt(5)*a(n)) < frac(sqrt(5)*a(n-1)).at n=28A079497
• Greedy frac multiples of sqrt(5): a(1)=1, sum(n>0,frac(a(n)*x))=1 at x=sqrt(5).at n=22A079936
• a(n) = floor((Fibonacci(2*n+1)+1)/2).at n=22A087953
• 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=21A099511
• Antidiagonal sums of number triangle A086645.at n=22A108479
• Expansion of (1-x)^3/(1-4x+5x^2-4x^3+x^4).at n=22A109961
• Triangle T(n, k) = 2*(-1 + 2*k)*T(n-1, k) - T(n-2, k) with T(-2, k) = T(-1, k) = 1, read by rows.at n=26A122053
• Negative of the Hankel transform of C(n) - C(n+2), where C = A000108.at n=21A138268
• Largest proper divisor of the Fibonacci numbers > 1.at n=42A139045
• Denominators of continued fraction convergents to sqrt(5/4).at n=14A153315
• Array read by antidiagonals of a(n) = a(n-1)*k-((k-1)/(k^n)) where a(0)=1 and k=(sqrt(x^2+1)+x)^2 for integers x>=1.at n=37A188647
• Hypotenuses of primitive Pythagorean triples in A195547 and A195548.at n=21A195549
• One half of the even Markoff nunbers.at n=22A388289