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%I #9 May 28 2017 07:56:43
%S 2,211,2111,111121,111211,112111,1111211,1111111121,1111211111,
%T 1121111111,111111211111,111211111111,2111111111111,
%U 111111111111112111,111111112111111111,111111211111111111,112111111111111111
%N Primes with digital product = 2.
%C Corresponding indices of primes in A107611. Cf. A053666, A101987.
%H Harvey P. Dale, <a href="/A107612/b107612.txt">Table of n, a(n) for n = 1..684</a>
%F A107612(n) = prime(A107611(n)).
%p for i from 0 to 30 do it:=sum(10^j, j=0..i): for k from 0 to i do if isprime(it+10^k) then printf(`%d,`, it+10^k) fi: od:od: (Sellers)
%t Flatten[ Table[ Select[ Sort[ FromDigits /@ Permutations[ Flatten[{2, Table[1, {n}]}]]], PrimeQ[ # ] &], {n, 0, 19}]] (* _Robert G. Wilson v_, May 19 2005 *)
%t Select[Flatten[Table[FromDigits/@Permutations[PadRight[{2},n,1]],{n,20}]],PrimeQ]//Sort (* _Harvey P. Dale_, May 28 2017 *)
%Y Cf. A053666, A101987, A107611.
%Y Cf. A004022, A107689, A107690, A107691, A107692, A107693, A107694, A107695, A107696, A107697, A107698.
%K base,nonn
%O 1,1
%A _Zak Seidov_, May 17 2005
%E More terms from _Robert G. Wilson v_ and _James A. Sellers_, May 19 2005
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