A332922 2*a(n) are the perimeters of distinct triangles with integer sides i <= j <= k, whose area equals 2 times their perimeter. Terms occurring more than once belong to different triangles.

21, 24, 27, 30, 33, 36, 39, 42, 42, 45, 60, 66, 75, 81, 99, 105, 171, 306

Offset

1,1

Comments

There are 18 integer-sided triangles with 2*area = perimeter, with terms 42 corresponding to a pair of such triangles with different sides.

Links

Table of n, a(n) for n=1..18.

Crossrefs

Equals A289218/2.

Cf. A289219, A289220, A289221, A332879, A289253 (all merging terms for triangles with identical perimeters, but different sides).

Sequence in context: A302514 A303313 A257642 * A066867 A111356 A344806

Adjacent sequences: A332919 A332920 A332921 * A332923 A332924 A332925

Keyword

nonn,fini,full

Author

Hugo Pfoertner, Mar 02 2020

Status

approved