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A261970
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Numbers whose base-b expansions, for both b=3 and b=4, include no digits other than 0 and b-1.
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3
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0, 60, 240, 13308, 52992, 53052, 53196, 3195132, 3208140, 3346188, 12795648, 12795900, 871563264, 871563312, 871563456, 871576368, 871576380, 871576524, 871615728, 871616268, 871616448, 1072939776, 1072939788, 1072939824, 3225157884, 3472949196, 3473670912
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OFFSET
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1,2
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LINKS
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EXAMPLE
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60 is 2020 in base 3 and 330 in base 4; it uses the largest digits in the two bases (including 0's) and is therefore a term.
Similarly 240 is 22220 in base 3 and 3300 in base 4 so it is also a term.
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PROG
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(PARI) isokb(n, b) = {if (!n, return (1)); my(d = digits(n, b)); (#vecsort(d, , 8)==2) && (vecmin(d) == 0) && (vecmax(d) == b - 1); }
isok(n) = isokb(n, 3) && isokb(n, 4); \\ Michel Marcus, Sep 22 2015
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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