A332925 6*a(n) are the perimeters of distinct triangles with integer sides i <= j <= k, whose area equals 5 times their perimeter. Terms occurring more than once belong to different triangles.

18, 20, 21, 22, 22, 25, 27, 28, 28, 30, 31, 35, 36, 44, 46, 50, 52, 53, 58, 68, 68, 69, 76, 77, 77, 84, 86, 99, 105, 108, 124, 134, 145, 151, 154, 182, 182, 209, 210, 242, 252, 260, 266, 391, 407, 468, 629, 742, 901, 910, 1751, 3434

Offset: 1

Author

Hugo Pfoertner, Mar 02 2020

Keywords

• nonn
• fini
• full

Comments

There are 52 integer-sided triangles with 5*area = perimeter, with terms 22, 28, 68, 77, and 182 corresponding to pairs of such triangles with different sides.

Crossrefs

The 47 terms of A289221, divided by 30, are all terms of this sequence, but omitting distinct triangles with identical perimeters.