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A004623 Divisible only by primes congruent to 5 mod 7. 1
1, 5, 19, 25, 47, 61, 89, 95, 103, 125, 131, 173, 229, 235, 257, 271, 305, 313, 361, 383, 397, 439, 445, 467, 475, 509, 515, 523, 593, 607, 625, 655, 677, 691, 719, 733, 761, 859, 865, 887, 893, 929, 971, 1013 (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]==5&)/@FactorInteger[n][[All, 1]]; Select[Range[5000], ok] (* Vincenzo Librandi, Aug 20 2012 *)

PROG

(Magma) [n: n in [1..2000] | forall{d: d in PrimeDivisors(n) | d mod 7 eq 5}]; // Vincenzo Librandi, Aug 20 2012

CROSSREFS

Sequence in context: A106957 A236167 A022143 * A018475 A119238 A218885

Adjacent sequences: A004620 A004621 A004622 * A004624 A004625 A004626

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 27 03:51 EST 2022. Contains 358362 sequences. (Running on oeis4.)