1476984
domain: N
Appears in sequences
- Smallest leg in right triangle with relatively prime sides and hypotenuse 5^n.at n=9A036842
- a(n) = 5^n*sin(2n*arctan(1/2)) or numerator of tan(2n*arctan(1/2)).at n=9A066770
- Let (A,B)=(a(2*n),a(2*n+1)), then (A,B) is (even,odd), gcd(A,B)=1 and A^2 + B^2 = 5^n. Note: a(0)=0.at n=40A098122
- Expansion of 1/(1 - 4*x + 5*x^2).at n=19A099456
- Imaginary part of (4 + 3i)^n.at n=9A139031
- Values of x such that x^2 + y^2 = 5^n with x and y coprime and 0 < x < y.at n=19A230710