A309425 Difference x-y of generator pairs (x,y) {x and y coprime and not both odd, x > y} of primitive Pythagorean triangles, sorted by x and y (for same x).

1, 1, 3, 1, 3, 1, 5, 1, 5, 3, 1, 7, 5, 3, 1, 7, 5, 1, 9, 7, 3, 1, 9, 7, 5, 3, 1, 11, 7, 5, 1, 11, 9, 7, 5, 3, 1, 13, 11, 9, 5, 3, 1, 13, 11, 7, 1, 15, 13, 11, 9, 7, 5, 3, 1, 15, 13, 11, 9, 7, 5, 3, 1, 17, 13, 11, 7, 5, 1, 17, 15, 13, 11, 9, 7, 5, 3, 1, 19, 17, 13, 11, 9, 7, 3, 1

Offset

1,3

Comments

This sequence is based on x and y (for same x) in increasing order, directly mapping to A094192 and A094193, while A126637 is sorted by the sum x+y.

Given any two of the four sequences below, primitive Pythagorean triangles can be generated.

A094192: the bigger one in generator pairs;

A094193: the smaller one in generator pairs;

A309424: the sum of generator pairs;

A309425: the difference of generator pairs.

Links

Table of n, a(n) for n=1..86.

Formula

a(n) = A094192(n) - A094193(n).

Crossrefs

Cf. A094192, A094193, A126637, A309424.

Sequence in context: A216319 A355001 A337713 * A218355 A103790 A249947

Adjacent sequences: A309422 A309423 A309424 * A309426 A309427 A309428

Keyword

nonn

Author

Rui Lin, Jul 31 2019

Status

approved