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A129985
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Multiplicative persistence of the prime numbers.
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1
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0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 3, 2, 3, 1, 2, 1, 2, 3, 2, 3, 3, 1, 1, 1, 1, 1, 2, 1, 2, 3, 3, 1, 3, 2, 2, 2, 3, 1, 1, 3, 3, 2, 1, 2, 3, 3, 2, 3, 1, 2, 2, 3, 2, 2, 4, 2, 3, 3, 1, 1, 1, 2, 1, 3, 3, 2, 3, 3, 3, 3, 4, 3, 3, 4, 1, 1, 3, 1, 2, 3, 2, 3, 3, 2, 2, 3, 4, 3, 3, 3, 3, 1, 1, 2, 2, 2
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,10
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EXAMPLE
| 229 -> 2*2*9=36 -> 3*6=18 -> 1*8=8 -> persistence = 3
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MAPLE
| P:=proc(n) local i, k, w, ok, cont, x; for i from 1 by 1 to n do k:=ithprime(i); w:=1; ok:=1; x:=k; if k<10 then print(0); else cont:=1; while ok=1 do while k>0 do w:=w*(k-(trunc(k/10)*10)); k:=trunc(k/10); od; if w<10 then ok:=0; print(cont); else cont:=cont+1; k:=w; w:=1; fi; od; fi; od; end: P(100);
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CROSSREFS
| Sequence in context: A072499 A060272 A174713 * A085243 A092243 A194509
Adjacent sequences: A129982 A129983 A129984 * A129986 A129987 A129988
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KEYWORD
| easy,nonn,base
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), Jun 14 2007
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