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A280824
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Numbers with an even number of digits and with an even number of distinct digits.
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4
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10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 1000, 1001, 1010
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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LINKS
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Eric Weisstein's World of Mathematics, Digit
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FORMULA
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MAPLE
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isA280824 := proc(n)
if n < 10 then
return false;
end if;
dgs := convert(n, base, 10) ;
if type(nops(dgs), 'even') then
type(nops(convert(dgs, set)), 'even') ;
else
false;
end if;
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MATHEMATICA
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Select[Range[1010], Mod[Length[IntegerDigits[#1]], 2] == 0 && Mod[Length[Union[IntegerDigits[#1]]], 2] == 0 & ]
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PROG
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(Python)
def ok(n): s = str(n); return len(s)%2 == 0 == len(set(s))%2
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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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