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A103253 Numbers y, without duplication, in Pythagorean triples x,y,z where x,y,z are relatively prime composite numbers and z is a perfect square. 0
7, 28, 41, 63, 112, 119, 161, 164, 175, 239, 252, 343, 369, 448, 476, 527, 567, 644, 656, 700, 721, 847, 956, 959, 1008, 1025, 1071, 1081, 1183, 1241, 1372, 1449, 1476, 1519, 1575, 1792, 1904, 2009, 2023, 2047, 2108, 2268, 2527, 2576, 2624, 2800, 2884, 2975 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The case where x or y and z are squares does not occur.

LINKS

Table of n, a(n) for n=1..48.

MathForFun, Pythagorean triples

Chenglong Zou, Peter Otzen, Cino Hilliard, Pythagorean triplets, digest of 6 messages in mathfun Yahoo group, Mar 19, 2005.

EXAMPLE

x=24, y=7, 24^2 + 7^2 = 25^2. 7 is the 1st entry in the list.

PROG

(PARI) pythtrisq(n) = { local(a, b, c=0, k, x, y, z, vy, wx, vx, vz, j); w = vector(n*n+1); for(a=1, n, for(b=1, n, x=2*a*b; y=b^2-a^2; z=b^2+a^2; if(y > 0 & issquare(z), c++; w[c]=y; print(x", "y", "z) ) ) ); vy=vector(c); w=vecsort(w); for(j=1, n*n, if(w[j]>0, k++; vy[k]=w[j]; ) ); for(j=1, 200, print1(vy[j]", ") ) }

CROSSREFS

Sequence in context: A267432 A155712 A015817 * A321777 A269451 A139607

Adjacent sequences:  A103250 A103251 A103252 * A103254 A103255 A103256

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Mar 20 2005

STATUS

approved

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Last modified May 16 12:46 EDT 2021. Contains 343947 sequences. (Running on oeis4.)