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A067106 a(n) = smallest number whose digit product equals n!/m where m is the product of all prime factors > 7 of n! (with multiplicity). 0
1, 2, 6, 38, 358, 2589, 25789, 257889, 2578899, 45578899, 45578899, 556788899, 556788899, 25567788899, 455577888999, 5557788888999, 5557788888999, 255577888889999, 255577888889999, 5555778888889999, 355557778888889999 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
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.
PROG
(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), ", "))}
CROSSREFS
Sequence in context: A275557 A197972 A068184 * A032111 A013703 A002031
KEYWORD
easy,nonn,base
AUTHOR
Amarnath Murthy, Jan 07 2002
EXTENSIONS
Edited, corrected and extended by Klaus Brockhaus, Jun 17 2003
STATUS
approved

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Last modified March 28 15:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)