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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
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
KEYWORD
nonn
AUTHOR
STATUS
approved