29681

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2), with a(0) = 1, a(1) = 1.at n=9A001835
• a(n) = 4*a(n-2) - a(n-4) for n > 1, a(n) = n for n = 0, 1.at n=17A002530
• a(n) = (1 + a(n-1)*a(n-2))/a(n-3), a(0) = a(1) = a(2) = 1.at n=18A005246
• 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=17A048788
• 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=15A075276
• a(n) = 4*a(n-1) - a(n-2) with a(1) = 1, a(2) = 3.at n=8A079935
• Square array of numbers T(n,k) = ((1+sqrt(3))*(k+sqrt(3))^n-(1-sqrt(3))*(k-sqrt(3))^n)/(2*sqrt(3)), read by antidiagonals.at n=63A086404
• Array T(k,n) read by antidiagonals. G.f.: x(1-x)/(1-kx+x^2), k>1.at n=63A094954
• Square array T(M,N) read by antidiagonals: number of dimer tilings of a 2*M X 2*N Moebius strip.at n=46A103997
• Triangle T(n, k) = (k*ChebyshevU(n, (k+2)/2) + 2*ChebyshevT(n+1, (k+2)/2))/2.at n=22A121872
• Expansion of x*(1 + x)*(1 - 3*x^2)/(1 - 4*x^2 + x^4).at n=18A122573
• Expansion of x*(1 + x)*(1 - 3*x^2)/(1 - 4*x^2 + x^4).at n=19A122573
• Numbers k such that k^2 is of the form 3*m^2 + 2*m + 1 (A056109).at n=4A122769
• #4 in an infinite set of generalized Pascal's triangles with trigonometric properties.at n=43A125077
• Number of Khalimsky-continuous functions with a three-point codomain.at n=14A131887
• Interleave denominators and numerators of convergents to sqrt(3).at n=24A140827
• a(n) = C(2,n) DELTA C(0,n).at n=45A147721
• Expansion of (1-2x-3x^2+x^3-x^5)/(1+4x^3+x^6).at n=23A157126
• Expansion of (1-2x-3x^2+x^3-x^5)/(1+4x^3+x^6).at n=24A157126
• a(n) = (1/2)*(n^3 - 6*n^2 + 13*n - 6).at n=40A158498