A145326 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.

4, 2, 3, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 2, 3, 1, 2, 3, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 3, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 1, 1, 2, 1, 1, 3, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2

Offset

1,1

Links

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

Example

f(1,1)=3, f(1,2)=11, f(1,3)=43, f(1,4)=171, so a(1)=4.

Crossrefs

Cf. A145325, A145327.

Sequence in context: A326046 A231169 A297847 * A178915 A222221 A254043

Adjacent sequences: A145323 A145324 A145325 * A145327 A145328 A145329

Keyword

easy,nonn

Author

Clark Kimberling, Oct 07 2008

Status

approved