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A038364
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Numbers n such that n = (product of digits of n) + (sum of digits of n).
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7
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OFFSET
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1,2
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COMMENTS
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A number n with m digits belongs to the sequence if K1*K2*K3*...*Km-9_(m-1)*K1-9_(m-2)*K2....=0 where Ki are the digits of n and 9_(m-1) is a repdigit with 9 repeated (m-1) times. Hence m=2, so sequence is complete.
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LINKS
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MAPLE
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select(proc(t) local d; d:= convert(t, base, 10); convert(d, `+`)+convert(d, `*`)=t end proc, [$0..100]); # Robert Israel, Dec 16 2014
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MATHEMATICA
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Select[Range[100], # == Times @@ IntegerDigits[#] + Plus @@ IntegerDigits[#] &] (* Michael De Vlieger, Dec 26 2014 *)
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PROG
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(PARI) isok(n) = my(d=digits(n)); n == (sum(i=1, #d, d[i]) + prod(i=1, #d, d[i])); \\ Michel Marcus, Apr 06 2014
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CROSSREFS
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KEYWORD
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fini,nonn,base,full
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AUTHOR
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STATUS
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approved
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