110771

Properties

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2), with a(0) = 1, a(1) = 1.at n=10A001835
• a(n) = 4*a(n-2) - a(n-4) for n > 1, a(n) = n for n = 0, 1.at n=19A002530
• a(n) = (1 + a(n-1)*a(n-2))/a(n-3), a(0) = a(1) = a(2) = 1.at n=20A005246
• a(2n+1) = a(2n) + a(2n-1), a(2n) = 2*a(2n-1) + a(2n-2); a(n) = n for n = 0, 1.at n=19A048788
• Generalized Markoff numbers: union of numbers a, b, c, d satisfying the Markoff(4) equation a^2 + b^2 + c^2 + d^2 = 4*a*b*c*d.at n=17A075276
• a(n) = 4*a(n-1) - a(n-2) with a(1) = 1, a(2) = 3.at n=9A079935
• Number of primes of the form 7k+2 less than 10^n.at n=6A091121
• Prime denominators of the rational convergents to sqrt(3).at n=5A096147
• Triangle T(n, k) = (k*ChebyshevU(n, (k+2)/2) + 2*ChebyshevT(n+1, (k+2)/2))/2.at n=29A121872
• Expansion of x*(1 + x)*(1 - 3*x^2)/(1 - 4*x^2 + x^4).at n=20A122573
• Expansion of x*(1 + x)*(1 - 3*x^2)/(1 - 4*x^2 + x^4).at n=21A122573
• Number of Khalimsky-continuous functions with a three-point codomain.at n=16A131887
• Interleave denominators and numerators of convergents to sqrt(3).at n=27A140827
• Pascal-like triangle with trigonometric properties, row sums = powers of 4; generated from shifted columns of triangle A180062.at n=54A180063
• a(n) gives y-values solving the Diophantine equation 2*x^2 + (x-1)^2 = y^2 for positive x.at n=4A189356
• Primes p such that there is a prime q satisfying 3*p^2 - q^2 = 2.at n=4A225431
• a(n) = a(n-1) + (if a(n-1) is odd a(n-2) else a(n-3)) with a(0) = 0, a(1) = 1.at n=28A254308
• Maximal term of TRIP-Stern sequence of level n corresponding to permutation triple (e,23,e).at n=34A271488
• a(n) = numerator(r(n)) where r(n) = (((1/2)*(sqrt(3) + 1))^n - ((1/2)*(sqrt(3) - 1))^n * cos(Pi*n))/sqrt(3).at n=19A305491
• a(n) = MPR2(n, 4), where MPR2(n, x) is the (monic) minimal polynomial of 2*cos(2*Pi/n) as defined in A232624.at n=37A309040