First 11 values of A121387 coincide with apparently unrelated new seq

[Jonathan Post]

Here's a strange coiuncidence that I hope someone can complain.

I started a new seq that might well be labeled "less" as it seems
arbitrary.  But it looked like an existing seq for 11 values before
differing.

Semiprimes which are the hypotenuses of primitive Pythagorean triples.
A001358 INTERSECTION A020882

If I list these with multiplicity (multiple primitive triples shown)
this begins:
n   a(n)  triple(s)
1   25     (7,24,25)
2   65     (16, 63, 65)
3   85     (13, 84, 85)
4   85     (36, 77, 85)
5   145   (77, 144, 145)
6   145   (24, 143, 145)
7   169   (119, 120, 169)
8   185   (57, 176, 185)
9   185   (104, 153, 185)
10 205   (133, 156, 205)
11 205   (84, 187, 205)
12 221   (21, 220, 221)
13 221   (140, 171, 221)
14 265   (23, 264, 265)
15 265   (96, 247, 265)
16 289   (161, 240, 289)
17 305   (207, 224, 305)
18 305   (136, 273, 305)
19 365   (27, 364, 365)
20 365   (76, 357, 365)

If I give the set of values (without multiplicity) it begins:

25, 65, 85, 145, 169, 185, 205, 221, 265, 289, 305, 365

The first 11 values are the same as the apparently unrelated A121387
which begins:
25, 65, 85, 145, 169, 185, 205, 221, 265, 289, 305, 329, 365, 377,
445, 481, 485, 493

but the 329 which is a(12) of A121387 is a semiprime (7 * 47) but is
NOT a primitive Pythagorean hypotenuse.

Just when I was about to make a conjecture, the Law of Small Numbers kicked in!

Any ideas?