The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A009129

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A009129

Perimeter of more than one Pythagorean triangle.
(history; published version)

#10 by Charles R Greathouse IV at Sat Feb 03 21:32:33 EST 2018

STATUS

editing

approved

#9 by Charles R Greathouse IV at Sat Feb 03 21:32:31 EST 2018

CROSSREFS

Cf. Subsequence of A010814.

#8 by Charles R Greathouse IV at Sat Feb 03 21:32:20 EST 2018

CROSSREFS

Cf. A010814.

STATUS

approved

editing

#7 by Charles R Greathouse IV at Sat Feb 03 21:31:15 EST 2018

STATUS

editing

approved

#6 by Charles R Greathouse IV at Sat Feb 03 21:31:12 EST 2018

LINKS

Charles R Greathouse IV, <a href="/A009129/b009129.txt">Table of n, a(n) for n = 1..10000</a>

PROG

(PARI) is(k)=my(m2, mm2, s); for(m=2, sqrtint(k\2), m2=2*m; mm2=2*m^2; forstep(n=if(m%2, 2, 1), min(k\m2-m, m-1), m%2+1, if(k%(mm2+m2*n)==0 && gcd(m, n)==1 && s++>1, return(1)))); 0 \\ Charles R Greathouse IV, Feb 03 2018

(PARI) list(lim)=my(v=List(), ct=Map(), m2, mm2, t); for(m=2, sqrtint(lim\2), m2=2*m; mm2=2*m^2; forstep(n=if(m%2, 2, 1), min(lim\m2-m, m-1), m%2+1, if(gcd(m, n)>1, next); t=mm2+m2*n; forstep(k=t, lim, t, mapput(ct, k, mapisdefined(ct, k))))); for(n=60, lim, if(mapisdefined(ct, n) && mapget(ct, n), listput(v, n))); ct=0; Vec(v) \\ Charles R Greathouse IV, Feb 03 2018

STATUS

approved

editing

#5 by Russ Cox at Fri Mar 30 18:35:07 EDT 2012

AUTHOR

_David W. Wilson (davidwwilson(AT)comcast.net)_

Discussion

Fri Mar 30

18:35

OEIS Server: https://oeis.org/edit/global/202

#4 by N. J. A. Sloane at Sat Sep 13 03:00:00 EDT 2003

KEYWORD

nonn,new

nonn

AUTHOR

David W. Wilson (davidwwilson(AT)attbicomcast.comnet)

#3 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003

KEYWORD

nonn,new

nonn

AUTHOR

dww

David W. Wilson (davidwwilson(AT)attbi.com)

#2 by N. J. A. Sloane at Mon May 08 03:00:00 EDT 2000

KEYWORD

nonn,new

nonn

AUTHOR

[email protected]

dww

#1 by N. J. A. Sloane at Sat Dec 11 03:00:00 EST 1999

NAME

Perimeter of more than one Pythagorean triangle.

DATA

60, 84, 90, 120, 132, 144, 168, 180, 210, 240, 252, 264, 270, 280, 288, 300, 312, 330, 336, 360, 390, 396, 408, 420, 432, 440, 450, 456, 462, 468, 480, 504, 510, 520, 528, 540, 546, 552, 560, 570, 576, 588, 600, 612, 616, 624, 630, 660, 672, 680, 684, 690, 700, 720

OFFSET

1,1

KEYWORD

nonn

AUTHOR

[email protected]

STATUS

approved