%I A024364
%S A024364 12,30,40,56,70,84,90,126,132,144,154,176,182,198,208,220,234,240,
%T A024364 260,286,306,312,330,340,374,380,390,408,418,420,442,456,462,476,
%U A024364 494,510,532,544,546,552,570,598,608,644,646,650,672,684,690,700
%N A024364 Consider primitive Pythagorean triangles (A^2 + B^2 = C^2, (A, B) = 1, 
               A <= B); sequence gives perimeters A+B+C.
%C A024364 Perimeters of primitive Pythagorean triples in increasing order.
%C A024364 n is in this sequence iff A070109(n)>0. This is a subset of A010814.
%H A024364 Ron Knott, <a href="http://www.mcs.surrey.ac.uk/Personal/R.Knott/Pythag/
               pythag.html">Pythagorean Triples and Online Calculators</a>
%p A024364 isA024364 := proc(an) local r::integer,s::integer ; for r from floor((an/
               4)^(1/2)) to floor((an/2)^(1/2)) do for s from r-1 to 1 by -2 do 
               if 2*r*(r+s) = an and gcd(r,s) < 2 then RETURN(true) ; fi ; if 2*r*(r+s) 
               < an then break ; fi ; od ; od : RETURN(false) ; end : for n from 
               2 to 400 do if isA024364(n) then printf("%d,",n) ; fi ; od ; - R. 
               J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 08 2006
%t A024364 lst={}; amx=99; Do[For[b=a+1, b<(a^2/2), c=(a^2+b^2)^(1/2); If[c==IntegerPart[c]&&GCD[a, 
               b, c]==1, p=a+b+c; AppendTo[lst, p]]; b=b+2], {a, 3, amx}]; lst [From 
               Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 08 2008]
%Y A024364 a(n)=2*A020886(n) (with different offset).
%Y A024364 Sequence in context: A115912 A083096 A145469 this_sequence A093507 A145470 
               A108278
%Y A024364 Adjacent sequences: A024361 A024362 A024363 this_sequence A024365 A024366 
               A024367
%K A024364 nonn
%O A024364 1,1
%A A024364 David W. Wilson (davidwwilson(AT)comcast.net)