A332927 6*a(n) are the perimeters of distinct triangles with integer sides i <= j <= k, whose area equals 7 times their perimeter. Terms occurring more than once belong to different triangles.

27, 28, 32, 33, 35, 38, 40, 42, 44, 44, 45, 48, 49, 52, 55, 57, 60, 62, 68, 70, 72, 80, 88, 90, 90, 92, 96, 101, 104, 108, 115, 126, 132, 136, 143, 145, 148, 149, 155, 158, 160, 161, 171, 176, 185, 192, 205, 205, 235, 236, 262, 270, 295, 304, 340, 348, 365, 396, 410, 477, 500, 535, 550, 600, 721, 750, 884, 900, 938, 957, 1023, 1055, 1287, 1700, 1972, 2277, 3333, 3350, 6567, 13002

Offset: 1

Author

Hugo Pfoertner, Mar 02 2020

Keywords

• nonn
• fini
• full

Comments

There are 80 integer-sided triangles with 7*area = perimeter, with terms 44, 90, and 205 corresponding to pairs of such triangles with different sides.

Crossrefs

The 77 terms of A289253, divided by 42, are all terms of this sequence, but omitting distinct triangles with identical perimeters.