OFFSET
1,1
COMMENTS
The inradius for isosceles triangle (a, b, b) is r = (a/2)*sqrt((2*b-a)/(2*b+a)).
If m is a term, so is k*m with k > 1; hence, A008592 \ {0} is a subsequence.
LINKS
Eric Weisstein's World of Mathematics, Incircle.
Eric Weisstein's World of Mathematics, Isosceles Triangle.
EXAMPLE
The smallest inradius, r = 10, corresponds to isosceles triangle (30, 39, 39).
The third inradius, r = 21, corresponds to isosceles triangle (56, 100, 100).
r = 60 is the first inradius for which there exist two such isosceles triangles: (168, 259, 259) and (180, 234, 234).
MATHEMATICA
Select[Range[300], Length @ Reduce[#^2 == a^2*(2*b - a)/(4*(2*b + a)) && 0 < a < b, {a, b}, Integers] > 0 &] (* Amiram Eldar, May 05 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Bernard Schott, Apr 29 2023
STATUS
approved