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%I #29 Jun 23 2023 10:52:18
%S 2,7,8,10,17,20,25,28,31,38,61,62,355,4690,4772,8162,10523,14716
%N Numbers k such that A007923(k) is prime.
%C SDS(355) certified prime with Primo.
%C No more terms <= 8000. - _XU Pingya_, May 30 2017
%H Jason Earls, <a href="http://www.gallup.unm.edu/~smarandache/SNBook14.pdf">Some Results Concerning the Smarandache Deconstructive Sequence</a>, Smarandache Notions Journal, Volume 14 Issue 1, January 2004, Pages 222-226 .
%o (PARI) isok(n) = my(m=(n*(n+1)/2-1)%9+1); isprime(sum(k=0, n-1, 10^k*((m-k-1)%9+1))); \\ _Michel Marcus_, May 30 2017
%Y Cf. A007923.
%K more,nonn
%O 1,1
%A _Jason Earls_, Oct 09 2002
%E a(14)-a(15) from _XU Pingya_, May 30 2017
%E a(16)-a(18) from _Michael S. Branicky_, Jun 22 2023
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