login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

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.
1

%I #6 Mar 02 2020 18:54:16

%S 27,28,32,33,35,38,40,42,44,44,45,48,49,52,55,57,60,62,68,70,72,80,88,

%T 90,90,92,96,101,104,108,115,126,132,136,143,145,148,149,155,158,160,

%U 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

%N 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.

%C 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.

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

%K nonn,fini,full

%O 1,1

%A _Hugo Pfoertner_, Mar 02 2020