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A064981 Numbers k such that k*10^10-1, k*10^10-3, k*10^10-7 and k*10^10-9 are all prime. 1
13532, 72938, 84614, 118802, 153854, 195725, 233642, 269750, 329621, 425381, 432449, 456401, 488633, 494345, 586346, 628883, 660005, 693500, 702563, 712199, 760196, 804485, 831188, 862790, 981359, 982922, 1040756, 1067657, 1105667 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..100

MATHEMATICA

Select[ Range[2 10^6], PrimeQ[10^10# - 1] && PrimeQ[10^10# - 3] && PrimeQ[10^10# - 7] && PrimeQ[10^10# - 9] &]

Select[Range[111*10^4], AllTrue[10^10 #+{-1, -3, -7, -9}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 21 2018 *)

PROG

(PARI) { n=0; for (m=1, 10^9, b=10^10*m; if(isprime(b - 1) && isprime(b - 3) && isprime(b - 7) && isprime(b - 9), write("b064981.txt", n++, " ", m); if (n==100, return)) ) } \\ Harry J. Smith, Oct 02 2009

CROSSREFS

Sequence in context: A257156 A254738 A342858 * A275370 A204785 A249526

Adjacent sequences:  A064978 A064979 A064980 * A064982 A064983 A064984

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Oct 30 2001

STATUS

approved

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Last modified August 3 19:05 EDT 2021. Contains 346441 sequences. (Running on oeis4.)