A305214 Numbers k such that A305212(k) is not zero.

7, 9, 14, 18, 21, 27, 28, 35, 36, 42, 45, 49, 54, 56, 63, 70, 72, 77, 81, 84, 90, 91, 98, 99, 105, 108, 112, 117, 119, 126, 133, 135, 140, 144, 147, 153, 154, 161, 162, 168, 171, 175, 180, 182, 189, 196, 198, 203, 207, 210, 216, 217, 224, 225, 231, 234, 238

Offset

1,1

Comments

Conjecture: These are simply the positive integers that are divisible by 7 or 9.

Links

Table of n, a(n) for n=1..57.

Prog

(Python) [n for n in range(100) if n != len(set((pow(x, 3, n) + pow(y, 3, n))%n for x in range(n) for y in range(n)))]
(PARI) isok(n) = my(v=[]); for (x=1, n, for (y=1, n, v = concat(v, Mod(x, n)^3 + Mod(y, n)^3))); n != #Set(v); \\ Michel Marcus, Jul 10 2018

Crossrefs

Cf. A305211, A305212.

Sequence in context: A320699 A332514 A353168 * A319877 A020939 A282758

Adjacent sequences: A305211 A305212 A305213 * A305215 A305216 A305217

Keyword

nonn

Author

Jack Zhang, May 27 2018

Extensions

a(25)-a(57) from Jon E. Schoenfield, May 28 2018

Status

approved