A247679 Composite numbers congruent to 17 modulo 18.

35, 125, 143, 161, 215, 287, 305, 323, 341, 377, 395, 413, 485, 539, 575, 611, 629, 665, 737, 755, 791, 845, 899, 917, 935, 989, 1007, 1025, 1043, 1079, 1115, 1133, 1169, 1205, 1241, 1295, 1313, 1331, 1349, 1385, 1403, 1421, 1457, 1475

Offset: 1

Author

Odimar Fabeny, Sep 22 2014

Keywords

• nonn
• easy

Comments

Subsequence of A017257 (9n + 8).

Links

• Odimar Fabeny, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A017257, A247676, A247678, A247681, A247682, A247683.

Programs

Mathematica

Select[18Range[100] - 1, Not[PrimeQ[#]] &] (* Alonso del Arte, Sep 25 2014 *)
Select[Range[17,1500,18],CompositeQ] (* Harvey P. Dale, Jun 19 2022 *)

PARI

lista(nn) = {forcomposite(n=1, nn, if ((n % 2) && ((n % 9) == 8), print1(n, ", ")); ); } \\ Michel Marcus, Sep 22 2014

Formula

a(n) ~ 18n. - Charles R Greathouse IV, Sep 27 2014