A165237 Long legs of primitive Pythagorean triples (a,b,c) for which 2a+1, 2b+1 and 2c+1 are primes.

21, 56, 285, 483, 783, 999, 1269, 1593, 1911, 2613, 3003, 3596, 3621, 3740, 4136, 4233, 4928, 5096, 5451, 5828, 5840, 6320, 7040, 7280, 8036, 8468, 9021, 9296, 9591, 11660, 12075, 12573, 12705, 12920, 12956, 13563, 14396, 14595, 15429, 15561

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Sep 09 2009

Keywords

• nonn

Examples

			See A165236.
		

Crossrefs

Cf. A020883, A165236, A156238.

Programs

Mathematica

amax=6*10^4;lst={};k=0;q=12!;Do[If[(e=((n+1)^2-n^2))>amax,Break[]];Do[If[GCD[m,n]==1,a=m^2-n^2;If[PrimeQ[2*a+1],b=2*m*n;If[PrimeQ[2*b+1],If[GCD[a,b]==1,If[a>b,{a,b}={b,a}];If[a>amax,Break[]];c=m^2+n^2;If[PrimeQ[2*c+1],k++;AppendTo[lst,b]]]]]];If[a>amax,Break[]],{m,n+1,12!,2}],{n,1,q,1}];Union@lst