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A072208 a(n)-th factorial is the smallest factorial containing exactly n 8's, or 0 if no such number exists. 8

%I #7 Mar 12 2015 19:14:38

%S 11,9,36,16,30,27,39,33,44,58,56,64,80,70,72,94,97,71,108,143,120,134,

%T 118,162,125,133,151,137,138,159,169,197,184,171,178,176,206,177,191,

%U 208,207,240,252,232,239,270,229,308,243,223,278,257,250,0,303,242,311

%N a(n)-th factorial is the smallest factorial containing exactly n 8's, or 0 if no such number exists.

%C It is conjectured that a(54)=0 since no factorial < 10000 contained just 54 eights.

%e a(2)=9 since 9th factorial i.e. 9!=362880 contains exactly two 8's.

%t Do[k = 1; While[ Count[IntegerDigits[k! ], 8] != n, k++ ]; Print[k], {n, 1, 60}]

%t Transpose[Flatten[Table[Select[Table[{n,DigitCount[n!,10,8]},{n,500}], Last[#] == i&,1],{i,50}],1]][[1]] (* _Harvey P. Dale_, Sep 13 2013 *)

%Y Cf. A072237, A072220, A072204, A072200, A072199, A072178, A072177, A072163, A072124.

%K base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Jul 30 2002

%E Edited and extended by _Robert G. Wilson v_, Jul 31 2002

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