A336889 a(n) gives one half of the length of row n of the irregular triangle A336888.

1, 1, 1, 2, 2, 3, 4, 1, 7, 6, 5, 8, 5, 5, 9, 10, 9, 13, 10, 5, 7

Offset

1,4

Comments

a(n) gives the number of nonrectangular triangles (sqrt(x(n)_j), sqrt(y(n)_j), sqrt(z(n))) with positive integer pairs (x(n)_j, y(n)_j), for j = 1, 2, ..., a(n), from row n of A336888 such that the areas A(n)_j are positive integers, and the quartets (x(n)_j, y(n)_j, z(n), A(n)_j) are primitive. z(n) = A337215(n), and the areas are given in A337216(n, j).

Links

Table of n, a(n) for n=1..21.

Crossrefs

Cf. A336888, A337215, A337216.

Sequence in context: A369475 A008951 A119473 * A002122 A105689 A351080

Adjacent sequences: A336886 A336887 A336888 * A336890 A336891 A336892

Keyword

nonn,more

Author

Wolfdieter Lang, Aug 19 2020

Status

approved