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A256341
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Numbers which have only digits 8 and 9 in base 10.
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9
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8, 9, 88, 89, 98, 99, 888, 889, 898, 899, 988, 989, 998, 999, 8888, 8889, 8898, 8899, 8988, 8989, 8998, 8999, 9888, 9889, 9898, 9899, 9988, 9989, 9998, 9999, 88888, 88889, 88898, 88899, 88988, 88989, 88998, 88999, 89888, 89889
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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Flatten[Table[FromDigits[#, 10]&/@Tuples[{8, 9}, n], {n, 5}]]
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PROG
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(Magma) [n: n in [1..35000] | Set(IntegerToSequence(n, 10)) subset {8, 9}];
(PARI) A256341(n)=vector(#n=binary(n+1)[2..-1], i, 10^(#n-i))*n~+10^#n\9*8
(Magma) [n: n in [1..100000] | Set(Intseq(n)) subset {8, 9}]; // Vincenzo Librandi, Aug 19 2016
(Python)
def a(n): return int(bin(n+1)[3:].replace('0', '8').replace('1', '9'))
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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