|
|
A097442
|
|
Integer part of the area of consecutive prime sided isosceles triangles.
|
|
0
|
|
|
2, 7, 16, 36, 64, 102, 144, 198, 306, 397, 520, 676, 774, 898, 1116, 1396, 1575, 1819, 2097, 2264, 2557, 2883, 3267, 3835, 4296, 4533, 4830, 5080, 5394, 6426, 7275, 7881, 8285, 9159, 9784, 10392, 11213, 11879, 12651, 13555, 14080, 15221, 16016, 16573
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
2,1
|
|
COMMENTS
|
The real part of these numbers is always irrational.
|
|
LINKS
|
|
|
FORMULA
|
Consider prime isosceles triangles of sides (2, 3, 3), (3, 5, 5), ..., (x, y, y) where x is prime and y is the next prime after x. Then area = 1/2*x*sqrt(y^2-(x/2)^2). Output floor(area)
|
|
PROG
|
(PARI) f(n) = forprime(x=2, n, y=nextprime(x+1); a=1/2*x*sqrt(y^2-(x/2)^2); print1(floor (a)", "))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|