A137228 - OEIS

%I #2 Mar 30 2012 18:49:09

%S 3,5,7,9,11,12,14,16,18,19,21,23,24,26,28,29,31,33,34,36,38,39,41,42,

%T 44,46,47,49,51,52,54,55,57,59,60,62,63,65,67,68,70,71,73,75,76,78,79,

%U 81,83,84,86,87,89,90,92,94,95,97,98,100,102,103,105,106,108,109,111,113

%N Minimal total number of edges in a polyiamond consisting of n triangular cells.

%F a(n) = (3n + A067628(n))/2.

%Y Cf. A135708, A067628, A000577.

%K nonn

%O 1,1

%A _Tanya Khovanova_, Mar 07 2008