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%I #13 Mar 20 2015 19:16:41
%S 1,2,5,29,30,108,679,4478,8736,17000,22427,22731
%N Numbers n such that 156/101*(10^(4n)-1)-1 is prime.
%C If n is in the sequence then m=91*(156/101*(10^(4n)-1)-1) is a term of A072394. Namely if n is a term of this sequence then for m=1/101*(14196*10^(4n)-23387), we have sigma(m)=reversal(m)-m (see comment lines of A072394).
%C Numbers corresponding to the larger terms are probable primes.
%C Next term exceeds 3500. - _Robert G. Wilson v_, Aug 08 2011.
%C a(13) > 40000. - _Robert Price_, May 23 2014
%t Select[Range[700], PrimeQ[156/101*(10^(4 #) - 1) - 1] &]
%Y Cf. A072394, A178321.
%K more,nonn
%O 1,2
%A _Farideh Firoozbakht_, May 26 2010
%E a(8)-a(12) from _Robert Price_, May 23 2014
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