A074235 - OEIS

%I #13 Jan 29 2024 19:12:20

%S 1,2,3,5,6,7,9,10,11,13,14,17,18,19,22,23,25,26,27,29,31,33,34,37,38,

%T 39,41,43,46,47,49,50,51,53,54,57,58,59,61,62,65,66,67,69,71,73,74,78,

%U 79,81,82,83,85,86,87,89,93,94,95,97,98,101,102,103,106,107,109,111

%N Numbers that cannot be a long leg of an integer right triangle.

%C The possible values of a long leg of an integer right triangle are in A009012.

%C A227481(a(n)) = 1. - _Reinhard Zumkeller_, Oct 11 2013

%H Reinhard Zumkeller, <a href="/A074235/b074235.txt">Table of n, a(n) for n = 1..1000</a>

%e 5 is a term because a^2 + 5^2 = c^2 has no solution for a < 5 with integers a, c.

%e 13 is a term because a^2 + 13^2 = c^2 has no solution for a < 13 with integers a, c.

%o (Haskell)

%o a074235 n = a074235_list !! (n-1)

%o a074235_list = filter ((== 1) . a227481) [1..]

%o -- _Reinhard Zumkeller_, Oct 11 2013

%Y Cf. A009012.

%Y Cf. A009023 (complement).

%K nonn

%O 1,2

%A _Zak Seidov_, Sep 18 2002