229771

Properties

Appears in sequences

• a(n) = 5*a(n-1) - a(n-2), with a(1)=1, a(2)=4.at n=8A004253
• Primes arising in A083989.at n=20A083990
• Expansion of g.f. (x^3+x^2+2*x+1)/(x^4+5*x^2+1).at n=16A101463
• Triangle T(n, k) = (k*ChebyshevU(n, (k+2)/2) + 2*ChebyshevT(n+1, (k+2)/2))/2.at n=23A121872
• Fifth in an infinite set of generalized Pascal's triangles, with trigonometric properties.at n=44A125078
• Numerators in continued fraction [0; 1, 3, 1, 3, 1, 3, ...].at n=16A136210
• Denominators in continued fraction [0; 1, 3, 1, 3, 1, 3, ...].at n=15A136211
• a(n) = (a(n-1)*a(n-3) + 1) / a(n-4) with a(0) = a(1) = a(2) = a(3) = 1.at n=27A217787
• Generalized Markoff numbers: union of numbers a, b, c, d, e satisfying the Markoff(5) equation a^2 + b^2 + c^2 + d^2 + e^2 = 5*a*b*c*d*e.at n=15A229242
• Column 2 of triangle in A288180.at n=25A333281
• Primes in A004253.at n=3A355982
• Prime numbersat n=20419