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A137228 Minimal total number of edges in a polyiamond consisting of n triangular cells. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 25 12:01 EDT 2019. Contains 324352 sequences. (Running on oeis4.)