login
Numbers that are not the sum, minus 1, of a Pythagorean triple.
6

%I #9 Oct 20 2024 03:35:00

%S 1,2,3,4,5,6,7,8,9,10,12,13,14,15,16,17,18,19,20,21,22,24,25,26,27,28,

%T 30,31,32,33,34,36,37,38,40,41,42,43,44,45,46,48,49,50,51,52,53,54,56,

%U 57,58,60,61,62,63,64,65,66,67,68,70,72,73,74,75,76,77,78,80,81,82,84

%N Numbers that are not the sum, minus 1, of a Pythagorean triple.

%C Numbers that are not in A136000.

%H Amiram Eldar, <a href="/A136002/b136002.txt">Table of n, a(n) for n = 1..10000</a>

%t q[n_] := EvenQ[n] || Module[{d = Divisors[(n+1)/2]}, AllTrue[Range[3, Length[d]], d[[#]] >= 2 * d[[#-1]] &]]; Select[Range[100], q] (* _Amiram Eldar_, Oct 19 2024 *)

%Y Cf. A009096, A010814, A136000.

%K nonn,changed

%O 1,2

%A _Omar E. Pol_, Dec 15 2007

%E Extended by _Ray Chandler_, Dec 13 2008