A071557 Numbers k such that A065876(k) = k^2-k+1.

0, 2, 3, 4, 5, 6, 7, 9, 10, 11, 14, 15, 16, 19, 20, 24, 25, 26, 29, 35, 36, 39, 40, 41, 45, 49, 51, 54, 56, 59, 61, 65, 66, 69, 71, 74, 79, 84, 85, 90, 94, 95, 101, 110, 116, 120, 121, 124, 126, 130, 131, 134, 139, 141, 145, 146, 150, 156, 159, 160, 165, 169, 170, 171

Offset: 1

Author

Benoit Cloitre, May 30 2002

Keywords

• easy
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A065876.

Programs

Mathematica

q[n_] := Module[{m = n+1}, While[!Divisible[m^2 + 1, n^2 + 1], m++]; m == n^2 - n + 1]; Select[Range[200], q] (* Amiram Eldar, May 05 2022 *)

PARI

for(n=0,300,q=n+1; while((q^2+1)%(n^2+1)>0,q++); if(q==n^2-n+1,print1(n,",")))

Extensions

a(1) = 0 added by Amiram Eldar, May 05 2022