A298079 The number of triangles (up to congruence) with integer coordinates and perimeter in [n, n+1).

1, 2, 2, 6, 7, 11, 15, 26, 24, 42, 41, 66, 60, 83, 99, 126, 127, 176, 179, 219, 217, 302, 283, 374, 366, 456, 446, 551, 573, 640, 667, 808, 805, 938, 936, 1123, 1078, 1286, 1276, 1464, 1487, 1699, 1710, 1909, 1912, 2193, 2161, 2447, 2489, 2806, 2749, 3064, 3111

Offset

3,2

Links

Peter Kagey, Table of n, a(n) for n = 3..149

Peter Kagey, Integer Triangles with perimeter less than n, Programming Puzzles & Code Golf Stack Exchange.

Peter Kagey, Haskell program for A298079.

Example

For n = 3, all triangles with perimeter in [3, 4) are congruent to:
(0, 0), (0, 1), (1, 0) with perimeter 3.41....
For n = 4, all triangles with perimeter in [4, 5) are congruent to:
(0, 0), (0, 1), (1, 2) with perimeter 4.65..., or
(0, 0), (0, 2), (2, 0) with perimeter 4.82....
For n = 5, all triangles with perimeter in [5, 6) are congruent to:
(0, 0), (0, 2), (1, 2) with perimeter 5.23..., or
(0, 0), (1, 2), (2, 1) with perimeter 5.88....

Crossrefs

Cf. A051518, A298121.

Sequence in context: A338837 A079811 A097869 * A295783 A060303 A099577

Adjacent sequences: A298076 A298077 A298078 * A298080 A298081 A298082

Keyword

nonn

Author

Peter Kagey, Jan 11 2018

Status

approved