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A067106
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a(n) = smallest number whose digit product equals n!/m where m is the product of all prime factors > 7 of n! (with multiplicity).
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0
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1, 2, 6, 38, 358, 2589, 25789, 257889, 2578899, 45578899, 45578899, 556788899, 556788899, 25567788899, 455577888999, 5557788888999, 5557788888999, 255577888889999, 255577888889999, 5555778888889999, 355557778888889999
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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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For n = 12 we have n! = 479001600, m = 11 and n!/m = 43545600 = 5*5*6*7*8*8*8*9*9, so a(12) = 556788899.
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PROG
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(PARI) {for(n=1, 21, f=factor(n!); m=1; for(j=1, matsize(f)[1], if(f[j, 1]<=7, m=m*f[j, 1]^f[j, 2])); s=if(m>1, "", "1"); k=9; while(m>1, d=divrem(m, k); if(d[2]==0, s=concat(k, s); m=d[1], k--)); print1(eval(s), ", "))}
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CROSSREFS
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KEYWORD
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easy,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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