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A060610
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Repeatedly apply Euler phi to n-th prime; a(n) is the number terms in iteration chains which are not powers of 2 (number of initial iterations until reaching first power of 2).
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0
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0, 1, 1, 2, 2, 2, 1, 3, 3, 3, 2, 3, 2, 3, 4, 3, 4, 2, 3, 3, 3, 3, 3, 3, 2, 3, 2, 4, 4, 3, 4, 3, 2, 4, 4, 3, 3, 5, 4, 4, 4, 3, 4, 2, 4, 3, 3, 4, 4, 4, 4, 3, 2, 4, 1, 4, 4, 4, 4, 3, 5, 4, 3, 3, 3, 4, 3, 3, 5, 4, 3, 5, 3, 3, 5, 5, 3, 3, 3, 2, 4, 3, 4, 4, 4, 3, 3, 4, 4, 3, 5, 4, 6, 4, 4, 5, 5, 3, 4, 4, 4, 5, 4, 4, 4
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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FORMULA
| a(n)=A049115[A000040(n)]
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EXAMPLE
| n=100,p(100)=541, Phi-iteration chain is {541,540,144,48,16,8,4,2,1} with 9 terms. The first 4 terms (541,540,144,48) are not powers of 2, som a(100)=4.
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CROSSREFS
| Cf. A000040, A000010, A049108, A049113, A049116, A049115, A003434.
Sequence in context: A064659 A127953 A130267 * A017125 A063276 A055253
Adjacent sequences: A060607 A060608 A060609 * A060611 A060612 A060613
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KEYWORD
| easy,nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Apr 13 2001
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