A291747 Nonprimes of the form 7*k + 1.

1, 8, 15, 22, 36, 50, 57, 64, 78, 85, 92, 99, 106, 120, 134, 141, 148, 155, 162, 169, 176, 183, 190, 204, 218, 225, 232, 246, 253, 260, 267, 274, 288, 295, 302, 309, 316, 323, 330, 344, 351, 358, 365, 372, 386, 393, 400, 407, 414, 428, 435, 442, 456, 470, 477, 484, 498

Offset: 1

Author

Vincenzo Librandi, Aug 31 2017

Keywords

• nonn
• easy

Comments

Subsequence of A018252.

Crossrefs

Cf. A016993, A091113, A091300, A140444, A291745, A291746.

Programs

Magma

[n: n in [1..500 by 7] | not IsPrime(n)];

Mathematica

DeleteCases[7 Range[0, 200] + 1, _?PrimeQ]