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%I #25 Sep 07 2014 08:38:47
%S 611897345462967423035506688,98653640312161724942079430255181824,
%T 195052744758517664687371356106391552,
%U 69210613747809022824201189555756335104,401770033097538379880522919696423452672
%N Numbers of the form 2^r*19^s whose decimal representation contains each digit 0-9 a prime number of times.
%C See the formula section for more data, and others in cross-reference for similar and motivation.
%F A217431(n) = 2^A217429(n) * 19^A217430(n)
%e 2^55 * 19^8 has two copies of each of the digits 0, 1, 2, 7 and 9; three copies of each of 3, 4, 5 and 8; and five copies of the digit 6. All smaller numbers of the required type have at least a digit counted 0, 1, or a composite number of times, so this is a(1).
%t nd = 50; mx = 10^nd; pr = Prime@Range@PrimePi@nd; pQ[n_] := Union[DigitCount@n, pr] == pr; Sort@ Select[Flatten@ Table[2^p 19^q, {p, Log[2, mx/19]}, {q, Log[19, mx/2^p]}], pQ] (* _Giovanni Resta_, Jan 16 2014 *)
%Y Cf. A217854, A217429, A217430, A217404, A217407, A217410, A217413, A217416, A217419, A217422, A217425, A217431.
%K nonn,base,less
%O 1,1
%A _James G. Merickel_, Oct 05 2012
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