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Primes that are not the sum, minus 1, of a Pythagorean triple.
13

%I #9 Oct 20 2024 03:52:03

%S 2,3,5,7,13,17,19,31,37,41,43,53,61,67,73,97,101,103,109,113,127,137,

%T 151,157,163,173,193,211,229,241,257,271,277,281,283,293,313,317,331,

%U 337,353,367,397,401,409,421,433,457,463,487,499,521,523,541,547,557

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

%C Primes in A136002.

%H Amiram Eldar, <a href="/A136003/b136003.txt">Table of n, a(n) for n = 1..10000</a>

%t q[n_] := PrimeQ[n] && (n == 2 || Module[{d = Divisors[(n+1)/2]}, AllTrue[Range[3, Length[d]], d[[#]] >= 2 * d[[#-1]] &]]); Select[Range[600], q] (* _Amiram Eldar_, Oct 19 2024 *)

%Y Cf. A009096, A010814, A136002.

%K nonn,changed

%O 1,1

%A _Omar E. Pol_, Dec 16 2007

%E Extended by _Ray Chandler_, Dec 13 2008