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A145327 Least k such that f(n,k) is not a prime, where f(n,1)=4n+1 and f(n,k)=f(f(n,k-1)) for k>=2. 2
2, 1, 3, 2, 1, 1, 2, 1, 3, 2, 1, 1, 2, 1, 2, 1, 1, 3, 1, 1, 1, 2, 1, 3, 2, 1, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 3, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 3, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

f(1,1)=5, f(1,2)=21, so a(1)=2.

f(2,1)=9, so a(2)=1.

f(3,1)=13, f(3,2)=53, f(3,3)=213, so a(3)=3.

CROSSREFS

Cf. A145325, A145326.

Sequence in context: A144029 A166949 A114890 * A255191 A277818 A023512

Adjacent sequences:  A145324 A145325 A145326 * A145328 A145329 A145330

KEYWORD

easy,nonn

AUTHOR

Clark Kimberling, Oct 07 2008

STATUS

approved

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Last modified May 25 01:28 EDT 2019. Contains 323534 sequences. (Running on oeis4.)