|
| |
|
|
A070108
|
|
Number of integer triangles with perimeter n and prime side lengths which are obtuse and isosceles.
|
|
5
| |
|
|
0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
LINKS
| R. Zumkeller, Integer-sided triangles
|
|
|
EXAMPLE
| a(k)<=1 until k = 140, for k = 141 there are A005044(141)=432 integer triangles, a(141)=2 as
[37=37<67]: 37+37+67 = 141 and 2*(37^2)<67^2 and 37, 67 are primes,
[41=41<59]: 41+41+59 = 141 and 2*(41^2)<59^2 and 41, 59 are primes.
|
|
|
CROSSREFS
| Cf. A070080, A070081, A070082, A070101, A059169, A070088, A070092, A070103, A070106, A070135.
Sequence in context: A005088 A011686 A169671 * A011675 A096094 A011687
Adjacent sequences: A070105 A070106 A070107 * A070109 A070110 A070111
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 05 2002
|
| |
|
|
