The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.



(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046500 Smallest prime with multiplicative persistence n. 11


%S 2,11,29,47,277,769,8867,186889,2678789,26899889,3778888999,

%T 277777788888989

%N Smallest prime with multiplicative persistence n.

%C The persistence of a number is the number of times you need to multiply the digits together before reaching a single digit.

%H C. Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_022.htm">Puzzle page</a>

%H N. J. A. Sloane, <a href="http://neilsloane.com/doc/persistence.html">The persistence of a number</a>, J. Recreational Math., 6 (1973), 97-98.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence.</a>

%e 47 -> 28 -> 16 -> 6 has persistence 3.

%t 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 *)

%Y Cf. A003001, A014120.

%K nonn,base,more,hard,nice

%O 0,1

%A _Patrick De Geest_, Sep 15 1998

%E Value for n=10 and n=11 found by _Jud McCranie_

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 8 01:41 EST 2021. Contains 341934 sequences. (Running on oeis4.)