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 A165158 Hypotenuses of primitive Pythagorean triangles such that all 3 sides are composite. 3
 65, 85, 125, 145, 169, 185, 205, 221, 265, 289, 305, 325, 365, 377, 425, 445, 481, 485, 493, 505, 533, 545, 565, 625, 629, 685, 689, 697, 725, 745, 785, 793, 845, 865, 901, 905, 925, 949, 965, 985, 1025, 1037, 1073, 1105, 1145, 1157, 1165, 1189, 1205, 1241 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers C in triples of the form A^2+B^2=C^2, gcd(A,B,C)=1 and all of A, B and C in A002808. If multiple solutions exist for the same C, as for example (A,B,C) = (16,63,65) and (33,56,65), only one instance of C is added to the sequence. LINKS EXAMPLE (A,B,C) = (16,63,65), (36,77,85), (44,117,125) etc MATHEMATICA lst={}; Do[Do[If[IntegerQ[a=Sqrt[c^2-b^2]]&&GCD[a, b, c]==1, If[a>=b, Break[]]; If[ !PrimeQ[a]&&!PrimeQ[b]&&!PrimeQ[c], AppendTo[lst, c]]], {b, c-1, 4, -1}], {c, 5, 2000, 1}]; Union@lst CROSSREFS Cf. A020882, A165159 Sequence in context: A024508 A025303 A071011 * A084648 A224770 A274044 Adjacent sequences:  A165155 A165156 A165157 * A165159 A165160 A165161 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Sep 06 2009 EXTENSIONS Typo in description corrected by Alan Frank, Oct 09 2009 Definition clarified, comment moved to the examples and new comment added - R. J. Mathar, Oct 21 2009 STATUS approved

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Last modified November 27 01:16 EST 2021. Contains 349344 sequences. (Running on oeis4.)