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A004622 Divisible only by primes congruent to 4 mod 7. 1
1, 11, 53, 67, 109, 121, 137, 151, 179, 193, 263, 277, 347, 389, 431, 487, 557, 571, 583, 599, 613, 641, 683, 737, 739, 809, 823, 907, 977, 991, 1019, 1033, 1061, 1103, 1117, 1187, 1199, 1201, 1229, 1327, 1331, 1439, 1453, 1481, 1507, 1523, 1579, 1607, 1621 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

ok[1]=True; ok[n_]:=And@@(Mod[#, 7]==4&)/@FactorInteger[n][[All, 1]]; Select[Range[5000], ok] (* Vincenzo Librandi, Aug 20 2012 *)

PROG

[n: n in [1..2000] | forall{d: d in PrimeDivisors(n) | d mod 7 eq 4}]; // Vincenzo Librandi, Aug 20 2012

CROSSREFS

Sequence in context: A231386 A191099 A325727 * A045471 A086715 A178453

Adjacent sequences:  A004619 A004620 A004621 * A004623 A004624 A004625

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Offset changed from 0 to 1 by Vincenzo Librandi, Aug 20 2012

Missing a(41) added by Sean A. Irvine, Jun 08 2016

STATUS

approved

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Last modified December 13 09:48 EST 2019. Contains 329968 sequences. (Running on oeis4.)