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Multiplicative persistence of Cullen numbers.

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0, 0, 0, 2, 2, 1, 2, 2, 1, 1, 1, 2, 2, 1, 3, 2, 1, 2, 2, 2, 1, 1, 3, 2, 1, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`After the 111st element all the numbers have some digits equal to zero thus the persistence is equal to 1.`
	EXAMPLE	`Cullen number 65 --> 65=30 --> 30=0 thus persistence is 2.`
	MAPLE	`P:=proc(n) local i, k, w, ok, cont; for i from 0 by 1 to n do w:=1; k:=i2^i+1; ok:=1; 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(120);`
	CROSSREFS	`Cf. A002064, A131840.` `Sequence in context: A100244 A059689 A165018 this_sequence A087889 A014710 A055174` `Adjacent sequences: A131834 A131835 A131836 this_sequence A131838 A131839 A131840`
	KEYWORD	`easy,nonn,base`
	AUTHOR	`Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jul 20 2007`

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Last modified December 20 00:58 EST 2009. Contains 171054 sequences.

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