OFFSET
0,1
COMMENTS
For n > 1, a(n) is the smallest nonnegative k such that A216282(k) = n.
a(20) = 287793.
a(21) = 1499553.
a(22) = 11042163.
a(23) = 2832489.
a(24) = 863379.
a(25) = 20160657.
a(26) = 99379467.
a(27) = 5979699.
a(28) = 2590137.
a(30) = 3165723.
a(32) = 3933171.
a(33) = 121463793.
a(35) = 181445913.
a(36) = 9497169.
PROG
(PARI) b(n, k) = sum(i=0, sqrtint(n), sum(j=0, sqrtint(n\k), i^2+k*j^2==n));
a(n, k=2) = my(cnt=0); while(b(cnt, k)!=n, cnt++); cnt;
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Jul 02 2024
STATUS
approved