OFFSET
1,1
COMMENTS
It seems that A082867 is a subsequence.
The first counterexample to the above is A082867(60) = 258. - Charles R Greathouse IV, Jul 05 2022
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
8 is a term: 8 = 4+2+2 = 4^2 - 2^2 - 2^2.
15 is a term: 15 = 7+5+3 = 7^2 - 5^2 - 3^2.
MATHEMATICA
Solve[a==r^2-s^2-d^2 && 1<=r<=120 && 1<=s<=120 && 1<=d<=120 && 0<=a && r>s>=d && a==r+s+d, {a, r, s, d}, Integers]
PROG
(PARI) list(lim)=my(v=List([8])); lim\=1; for(a=3, lim-2, my(a2=a^2); for(b=(sqrt(2*a^2+2*a+1)-1)\2, a-2, my(t=a2-b^2-a-b, s); if(issquare(4*t+1, &s) && (c=(s-1)/2)<=b && c<=b && a+b+c<=lim, listput(v, a+b+c)))); Set(v) \\ Charles R Greathouse IV, Jul 05 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Mohammad Arab, Jul 04 2022
EXTENSIONS
a(57) = 184 inserted by Charles R Greathouse IV, Jul 05 2022
STATUS
approved