id:A129985 - OEIS Search Results

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Multiplicative persistence of the prime numbers.

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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; listen)

	OFFSET	`0,10`
	EXAMPLE	`229 -> 229=36 -> 36=18 -> 18=8 -> persistence = 3`
	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);`
	CROSSREFS	`Sequence in context: A072504 A072499 A060272 this_sequence A085243 A092243 A054716` `Adjacent sequences: A129982 A129983 A129984 this_sequence A129986 A129987 A129988`
	KEYWORD	`easy,nonn,base`
	AUTHOR	`Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jun 14 2007`

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Last modified December 5 08:23 EST 2009. Contains 170348 sequences.

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