OFFSET
1,2
COMMENTS
It seems that all positive integers are included.
Every term is equal to (d-1)/2 with d = 2*u*v - v^2, semiperimeter s = (h+b+c)/2 = u*v with b > c, h^2 = b^2 + c^2, u < v < 2*u, v odd (see Theorem 3 of Witcosky).
LINKS
EXAMPLE
From Michel Marcus, Mar 07 2018: (Start)
The first 10 terms of A081859 are 3, 5, 8, 7, 20, 12, 9, 28, 11, 16;
The first 10 terms of A081872 are 4, 12, 15, 24, 21, 35, 40, 45, 60, 63;
So the first 10 odd legs are 3, 5, 15, 7, 21, 35, 9, 45, 11, 63;
So the first 10 terms are 1, 2, 7, 3, 10, 17, 4, 22, 5, 31. (End)
MATHEMATICA
(* lists a0* have to be prepared before *)
opPT = {a020882, a046087, a046086, a020882 + a046087 + a046086};
topPT = Transpose[opPT]; stopPT = SortBy[topPT, {#[[4]]} &];
tstopPT = Transpose[stopPT]; nopPT = tstopPT;
Do[ If[OddQ[tstopPT[[2]][[k]]], nopPT[[2]][[k]] = tstopPT[[2]][[k]];
nopPT[[3]][[k]] = tstopPT[[3]][[k]], nopPT[[2]][[k]] = tstopPT[[3]][[k]];
nopPT[[3]][[k]] = tstopPT[[2]][[k]]], {k, 1, 10000}]; (nopPT[[2]] - 1)/2
CROSSREFS
KEYWORD
nonn
AUTHOR
Ralf Steiner, Jan 11 2018
STATUS
approved