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%I #16 Dec 04 2016 03:57:46
%S 21,27,29,61,67,111,151,191,201,203,223,241,313,319,331,351,373,397,
%T 403,409,461,463,481,553,559,571,667,711,791,807,841,869,889,931,979,
%U 1071,1079,1107,1129,1189,1257,1273,1277,1297,1431,1437,1583,1611,1639
%N Numbers of more than one digit that yield primes when cast in their own base.
%C All terms are coprime to 10. - _Robert Israel_, Dec 04 2016
%H Robert Israel, <a href="/A064507/b064507.txt">Table of n, a(n) for n = 1..10000</a>
%e E.g. 21 in base 21 is 2*21+1=43, 111 is 1*111*111+1*111+1=12433, etc.
%p filter:= proc(n) local L,i;
%p L:= convert(n,base, 10);
%p isprime(add(L[i]*n^(i-1),i=1..nops(L)))
%p end proc:
%p select(filter, [seq(i,i=11..2000,2)]); # _Robert Israel_, Dec 04 2016
%o (PARI) isok(n) = (n>=10) && isprime(fromdigits(digits(n), n)); \\ _Michel Marcus_, Dec 04 2016
%Y Cf. A064508. Contained in A054684.
%K nonn,base
%O 1,1
%A _Jon Perry_, Oct 06 2001
%E Offset corrected by _Arkadiusz Wesolowski_, Oct 19 2013
%E Name corrected by _Robert Israel_, Dec 04 2016
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