

A263772


Perimeters of integersided scalene triangles.


0



9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79
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OFFSET

1,1


COMMENTS

All natural numbers larger than 8 except 10.
Equivalently, numbers n that can be partitioned into three distinct parts a, b, and c, where a + b > c, a + c > b, and b + c > a (or, without loss of generality, into (a, b, c) with a < b < c < a + b). A subsequence of A009005. The unique terms in A107576.
For k > 2, (k1, k, k+1) gives perimeter 3k and (k1, k+1, k+2) gives perimeter 3k + 2. For k > 3, the scalene triangle (k1, k, k+2) has perimeter 3k + 1.


LINKS



FORMULA

a(n) = n + 9 for n > 1.


EXAMPLE

The integersided scalene triangle of least perimeter has sides of lengths 2, 3, and 4, so a(1) = 2 + 3 + 4 = 9.


PROG

(PARI) vector(100, n, if(n==1, 9, n+9)) \\ Altug Alkan, Oct 28 2015


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



