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A346383
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Numbers that leave their digital root as the remainder when the product of their digits is divided by the sum of their digits.
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1
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37, 38, 39, 73, 83, 93, 99, 146, 164, 247, 274, 299, 339, 348, 368, 384, 386, 393, 416, 427, 438, 449, 461, 472, 483, 494, 614, 638, 641, 679, 683, 697, 699, 724, 742, 769, 796, 834, 836, 843, 863, 929, 933, 944, 967, 969, 976, 992, 996, 1149, 1156, 1165, 1179
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OFFSET
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1,1
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LINKS
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EXAMPLE
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3*7 == 1 (mod 3+7), digital root of 37 is 1, so 37 is a term.
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MAPLE
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filter:= proc(n) local L; L:= convert(n, base, 10); convert(L, `*`) mod convert(L, `+`) = [9, $1..8][(n mod 9)+1] end proc;
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MATHEMATICA
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l={}; Do[If[Mod[Times@@IntegerDigits@n, Total[IntegerDigits[n]]]==FixedPoint[Total[IntegerDigits[#, 10]] &, n], AppendTo[l, n]], {n, 0, 1000}]; l
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PROG
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(PARI) isok(m) = my(d=digits(m)); (vecprod(d) % vecsum(d)) == ((m-1)%9 + 1); \\ Michel Marcus, Jul 15 2021
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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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STATUS
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approved
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