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A155171 Numbers p such that if q = p+1 then (a = q^2-p^2, b = 2*p*q, c = q^2 + p^2) is a primitive Pythagorean triple with s-1 and s+1 primes, where s = a+b+c.

%I A155171 #6 Jul 19 2022 16:22:56
%S A155171 1,2,7,10,20,29,44,50,65,70,76,77,101,104,107,115,154,175,197,202,226,
%T A155171 227,247,275,371,380,412,457,490,500,574,596,647,671,682,710,764,829,
%U A155171 926,1052,1085,1102,1127,1186,1204,1205,1225,1256,1280,1324,1325,1331
%N A155171 Numbers p such that if q = p+1 then (a = q^2-p^2, b = 2*p*q, c = q^2 + p^2) is a primitive Pythagorean triple with s-1 and s+1 primes, where s = a+b+c.
%e A155171 p=1,q=2,a=3,b=4,c=5,s=12-+1 primes.
%t A155171 lst={};Do[p=n;q=p+1;a=q^2-p^2;c=q^2+p^2;b=2*p*q;s=a+b+c;If[PrimeQ[s-1]&&PrimeQ[s+1],AppendTo[lst,n]],{n,8!}];lst
%Y A155171 Cf. A020882, A020886, A020884, A020883, A024364, A024406
%K A155171 nonn
%O A155171 1,2
%A A155171 _Vladimir Joseph Stephan Orlovsky_, Jan 21 2009
%E A155171 Definition edited by _N. J. A. Sloane_, Jul 19 2022