|
|
A130611
|
|
Tribonacci numbers A000073 which can be the hypotenuse of a Pythagorean triple.
|
|
1
|
|
|
13, 149, 274, 1705, 19513, 35890, 66012, 121415, 755476, 1389537, 4700770
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The first 2 values are hypotenuses of primitive Pythagorean triples, A000073 INTERSECTION A020882: (5^2 + 12^2 = 13^2), (51^2 + 140^2 = 149^2). The other values listed have one or more nonprimitive solution: a(6) = 35890 has 13 solutions; a(8), a(9), a(10), a(11) have 4 solutions each.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(4) = 1705 because 1023^2 + 1364^2 = 1705^2, which is a nonprimitive Pythagorean triple 341*(3,4,5).
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|