id:A131840 - OEIS Search Results

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Additive persistence of Cullen numbers.

+0
2

0, 0, 1, 2, 1, 2, 2, 2, 3, 1, 2, 2, 3, 2, 2, 2, 2, 3, 3, 3, 2, 3, 2, 2, 2, 2, 3, 2, 3, 2, 3, 3, 3, 2, 2, 3, 3, 3, 2, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 2, 3, 2, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 2, 2, 2, 2, 3, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 3, 2, 3, 3, 3, 3, 3 (list; graph; listen)

	OFFSET	`1,4`
	EXAMPLE	`Cullen number 385 --> 3+8+5=16 -->1+6=7 thus persistence is 2`
	MAPLE	`P:=proc(n) local i, k, w, ok, cont; for i from 1 by 1 to n do w:=0; 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, A131837.` `Sequence in context: A067995 A135551 A065531 this_sequence A057368 A085033 A096446` `Adjacent sequences: A131837 A131838 A131839 this_sequence A131841 A131842 A131843`
	KEYWORD	`easy,nonn,base`
	AUTHOR	`Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jul 20 2007`

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Last modified December 3 01:16 EST 2008. Contains 151161 sequences.

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