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A046500
Smallest prime with multiplicative persistence n.
11
2, 11, 29, 47, 277, 769, 8867, 186889, 2678789, 26899889, 3778888999, 277777788888989
OFFSET
0,1
COMMENTS
The persistence of a number is the number of times you need to multiply the digits together before reaching a single digit.
LINKS
C. Rivera, Puzzle page
N. J. A. Sloane, The persistence of a number, J. Recreational Math., 6 (1973), 97-98.
Eric Weisstein's World of Mathematics, Multiplicative Persistence.
EXAMPLE
47 -> 28 -> 16 -> 6 has persistence 3.
MATHEMATICA
a[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&, n, #>9&]]-1; t={}; i=1; Do[While[a[p=Prime[i]]!=n, i++]; AppendTo[t, p], {n, 0, 9}]; t (* Jayanta Basu, Jun 02 2013 *)
CROSSREFS
Sequence in context: A136317 A090389 A061238 * A062123 A345213 A117560
KEYWORD
nonn,base,more,hard,nice
AUTHOR
Patrick De Geest, Sep 15 1998
EXTENSIONS
Value for n=10 and n=11 found by Jud McCranie
STATUS
approved