A236571 Value of x for solution of 5^n = x^2 + y^2 with closest x and y (n >= 0, 0 <= x < y).

0, 1, 3, 5, 15, 38, 75, 190, 375, 950, 1875, 4750, 10296, 23750, 51480, 118750, 257400, 593750, 1287000, 2968750, 6435000, 14843750, 34182196, 74218750, 170910980, 371093750, 854554900, 1855468750, 4272774500, 9277343750, 21363872500, 46386718750

Offset

0,3

Comments

Corresponding values of y: 1,2,4,10,20,41,100,205,500,1025,2500,5125,11753,25625,58765 (A236572).

Links

Table of n, a(n) for n=0..31.

Mathematica

m = 30; Join[{0, 1}, Table[Reduce[{5^n == x^2+y^2, 0 ≤ x ≤ y}, {x, y}, Integers][[-1, 1, 2]], {n, 2, m}]]

Crossrefs

Cf. A121705, A236572.

Sequence in context: A138017 A280764 A148503 * A145939 A161703 A018551

Adjacent sequences: A236568 A236569 A236570 * A236572 A236573 A236574

Keyword

nonn

Author

Zak Seidov, Jan 29 2014

Status

approved