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%I #13 Jul 09 2023 06:13:25
%S 14,2,2,248,1856,7190,719,15308,13415,18434,13532,26975,6935,61763,
%T 17786,60140,6014,297974,103199,56321,80009,428186,303476,32558,
%U 1361063,444275,634451,116573,303593,293822,1068491,651464,1855937,3217754,364985,569129
%N Least k such that k*10^n-9, k*10^n-7, k*10^n-3 and k*10^n-1 are all prime.
%H Sean A. Irvine, <a href="/A064432/b064432.txt">Table of n, a(n) for n = 0..50</a>
%e a(1) = 2 because 19, 17, 13 and 11 are all prime.
%t Do[k = 1; While[ !PrimeQ[k*10^n - 1] || !PrimeQ[k*10^n - 3] || !PrimeQ[k*10^n - 7] || !PrimeQ[k*10^n - 9], k++ ]; Print[k], {n, 0, 35} ] (* _Robert G. Wilson v_ *)
%Y Cf. A064281.
%K nonn
%O 0,1
%A _Don Reble_, Oct 17 2001