A247683 Odd composite numbers congruent to 7 modulo 9.

25, 115, 133, 169, 187, 205, 259, 295, 385, 403, 475, 493, 511, 529, 565, 583, 637, 655, 745, 763, 781, 799, 817, 835, 871, 889, 925, 943, 961, 979, 1015, 1105, 1141, 1159, 1177, 1195, 1267, 1285, 1339, 1357, 1375, 1393, 1411, 1465, 1501

Offset

1,1

Comments

Subsequence of A017245 (9n + 7).

Links

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

Mathematica

Select[18Range[100] + 7, Not[PrimeQ[#]] &] (* Alonso del Arte, Sep 25 2014 *)
Select[Range[1, 1501, 2], CompositeQ[#]&&Mod[#, 9]==7&] (* or *) Select[Range[7, 1501, 18], CompositeQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 31 2021 *)

Prog

(PARI) lista(nn) = {forcomposite(n=1, nn, if ((n % 2) && ((n % 9) == 7), print1(n, ", ")); ); } \\ Michel Marcus, Sep 22 2014

Crossrefs

Cf. A017245, A247676, A247678, A247679, A247681, A247682.

Sequence in context: A160437 A050589 A340123 * A020152 A218493 A360511

Adjacent sequences: A247680 A247681 A247682 * A247684 A247685 A247686

Keyword

nonn,easy

Author

Odimar Fabeny, Sep 22 2014

Status

approved