A137228 Minimal total number of edges in a polyiamond consisting of n triangular cells.

3, 5, 7, 9, 11, 12, 14, 16, 18, 19, 21, 23, 24, 26, 28, 29, 31, 33, 34, 36, 38, 39, 41, 42, 44, 46, 47, 49, 51, 52, 54, 55, 57, 59, 60, 62, 63, 65, 67, 68, 70, 71, 73, 75, 76, 78, 79, 81, 83, 84, 86, 87, 89, 90, 92, 94, 95, 97, 98, 100, 102, 103, 105, 106, 108, 109, 111, 113

Offset

1,1

Links

Table of n, a(n) for n=1..68.

Formula

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

Crossrefs

Cf. A135708, A067628, A000577.

Sequence in context: A260392 A186346 A248633 * A186288 A272915 A094391

Adjacent sequences: A137225 A137226 A137227 * A137229 A137230 A137231

Keyword

nonn

Author

Tanya Khovanova, Mar 07 2008

Status

approved