

A305704


Numbers that are the semiperimeter of some triangle with integer sides and area.


2



6, 8, 9, 12, 15, 16, 18, 20, 21, 22, 24, 25, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 48, 49, 50, 52, 54, 55, 56, 57, 60, 63, 64, 65, 66, 68, 70, 72, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90, 91, 93, 95, 96, 98, 99, 100, 102, 104, 105
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OFFSET

1,1


LINKS

Peter Kagey, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Heronian Triangle


FORMULA

a(n) = A051518(n)/2.


MATHEMATICA

hp[p_] := Catch@ Block[{c, q=p/2}, Do[c = pab; If[IntegerQ@ Sqrt[q (qa) (qb) (qc)], Throw@ True], {a, p/21}, {b, p/2a+1, p/21}]; False]; Select[Range@ 105, hp[2 #] &] (* Giovanni Resta, Jun 14 2018 *)


CROSSREFS

Cf. A051518.
Sequence in context: A030725 A195101 A337381 * A043720 A191980 A304412
Adjacent sequences: A305701 A305702 A305703 * A305705 A305706 A305707


KEYWORD

nonn


AUTHOR

Peter Kagey, Jun 08 2018


STATUS

approved



