

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
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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

Table of n, a(n) for n=1..50.


EXAMPLE

(A,B,C) = (16,63,65), (36,77,85), (44,117,125) etc


MATHEMATICA

lst={}; Do[Do[If[IntegerQ[a=Sqrt[c^2b^2]]&&GCD[a, b, c]==1, If[a>=b, Break[]]; If[ !PrimeQ[a]&&!PrimeQ[b]&&!PrimeQ[c], AppendTo[lst, c]]], {b, c1, 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



