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A068501
Values m such that the consecutive pair parameters(m,m+1) generate Pythagorean triples whose odd terms are both prime.
8
1, 2, 5, 9, 14, 29, 30, 35, 39, 50, 65, 69, 90, 99, 135, 174, 189, 204, 224, 230, 260, 284, 285, 315, 320, 330, 369, 375, 410, 440, 464, 495, 515, 519, 525, 534, 545, 564, 575, 585, 590, 680, 719, 729, 744, 749, 765, 854, 870, 905, 915, 950, 974, 1080, 1119
OFFSET
1,2
COMMENTS
Setting u=m; v=m+1, triples (a,b,c) with a=u+v, b=2*u*v, c = u^2+v^2 = (a^2+1)/2 correspond to (A048161, A067755, A067756), a and c being both prime.
LINKS
Robert Simms, Deriving Pythagorean Triples (web archive)
MATHEMATICA
lst={}; Do[If[PrimeQ[(n+1)^2-n^2]&&PrimeQ[(n+1)^2+n^2], AppendTo[lst, n]], {n, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jun 01 2010 *)
Reap[Do[a=Prime[k]; If[PrimeQ[(a^2+1)/2], Sow[(a-1)/2]], {k, 2, 10^5}]][[2, 1]](* Zak Seidov, Apr 16 2011 *)
CROSSREFS
Cf. A051892.
Sequence in context: A291942 A071609 A377061 * A048071 A320996 A051892
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Mar 25 2002
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Jun 19 2002
STATUS
approved