login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A147856 Positive integers n such that n^2 = (x^4 - y^4)*(z^4 - t^4) where x>y and z>t are distinct pairs of integers with gcd(x,y)=gcd(z,t)=1. 3
520, 975, 2040, 3567, 7215, 7800, 9840, 13920, 19680, 30160, 40545, 53040, 57720, 62985, 95120, 108225, 138040, 151320, 180960, 230880, 247520, 286200, 289952, 352495, 473280, 535353, 546975, 720945, 769600, 1048560, 1141920, 1210560 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Positive integers n such that n^2 = A147858(m)*A147858(k) for positive integers k<m. Primitive elements of A147854: any element n of A147854 is of the form a(k)*s^2 for some positive integer s.

4*A196289(2*k) and A196289(2*k+1) belong to this sequence.

LINKS

Table of n, a(n) for n=1..32.

CROSSREFS

Sequence in context: A345855 A235274 A147854 * A094903 A250693 A200427

Adjacent sequences: A147853 A147854 A147855 * A147857 A147858 A147859

KEYWORD

nonn

AUTHOR

Max Alekseyev, Nov 18 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 7 17:10 EST 2023. Contains 360128 sequences. (Running on oeis4.)