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%I #39 Jun 28 2023 09:20:10
%S 4,7,52,100,136,388,30940,33250
%N Numbers k such that A037610(k) is prime.
%C The terms are a subset of the terms of A016777, since a term of A037610 can only be prime if it is congruent to 1 modulo 10 and hence congruent to 1 modulo 3. If A037610(k) is congruent to 1 modulo 3, then k is congruent to 1 modulo 3 as well.
%C No further terms up to 10000.
%e A037610(7) = 1231231 is prime, so 7 is a term of the sequence.
%t Select[Range@ 500, PrimeQ@ Floor[41/333*10^#] &] (* _Michael De Vlieger_, Sep 07 2015 *)
%o (PARI) a037610(n) = 10^n*41\333
%o is(n) = ispseudoprime(a037610(n))
%Y Cf. A037610, A062209.
%K nonn,more
%O 1,1
%A _Felix Fröhlich_, Sep 04 2015
%E a(7)-a(8) from _Michael S. Branicky_, Jun 28 2023
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