OFFSET
1,2
LINKS
Zhining Yang, Table of n, a(n) for n = 1..300
Zhining Yang, Blog
EXAMPLE
a(13) = 19 since 13 = (19^2 + 3)/(19 + 3^2) and there is no integer j < 19 such that 13 = (j^2 + k)/(j + k^2) with j > k > 1.
MATHEMATICA
Table[SelectFirst[Range[10^4], Function[j, AnyTrue[Range[j], Function[k, (j^2 + k)/(j + k^2) == n]]]], {n, 32}] (* Michael De Vlieger, Aug 16 2017 *)
PROG
(PARI) for(n=1, 100, for(b=1, 10^8, t=b*(b*n-1); a=floor((n+sqrt(n*n+4*t))/2); if(a*(a-n)==t, print1(a, ", "); break)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Zhining Yang, Jul 27 2017
STATUS
approved