login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242445 Numbers n such that there exist numbers 0 < a < b < n such that a+b, a+n, and b+n are square. 2
30, 44, 47, 48, 60, 66, 69, 70, 78, 86, 90, 92, 94, 95, 96, 98, 108, 113, 116, 118, 120, 122, 124, 125, 126, 132, 138, 142, 147, 150, 152, 154, 156, 157, 158, 159, 160, 165, 170, 176, 180, 182, 185, 186, 188, 190, 192, 194, 195, 196, 197, 198, 200, 207, 212, 214 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If n is a member then any n*m^2, m > 1, is too. - Zak Seidov, Sep 01 2014

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

30 is a member since the sum of each pair from {6, 19, 30} is square.

PROG

(PARI) is(n)=my(s=sqrtint(2*n-2)); for(A=sqrtint(n)+1, s-1, my(a=A^2-n); for(B=A+1, s, if(issquare(a+B^2-n), return(1)))); 0

CROSSREFS

Cf. A115040.

Sequence in context: A225326 A226727 A102843 * A062385 A164803 A152569

Adjacent sequences:  A242442 A242443 A242444 * A242446 A242447 A242448

KEYWORD

nonn

AUTHOR

Charles R Greathouse IV, May 14 2014

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 16 06:18 EST 2019. Contains 330016 sequences. (Running on oeis4.)