A098196 Smallest nonprime number which if used as initial term for iteration of the A000010[x] function, results in list-to-fixed-point of length=n, or 0 if no such number exists.

1, 0, 4, 8, 15, 25, 51, 85, 187, 289, 685, 1285, 2329, 4369, 10537, 18649, 35209, 66049, 150289, 281929, 598553, 1114129, 2387089, 4491589, 8978569, 16843009, 36087169, 71861329, 143163649, 286331153, 579117769, 1086374209, 2307492233

Offset

1,3

Comments

Remark: length-of-iteration means the number of distinct terms to fixed point [including start and end]. While number of iterations[=required operations] equals length-1.

The smallest composite number is the smallest product of primes in A007755 such that the phi-iteration has exactly n terms. [From T. D. Noe, Sep 18 2008]

Links

T. D. Noe, Table of n, a(n) for n=1..1002

Example

Iteration lists for the first 5 terms: {1},{0},{4,2,1},{8,4,2,1},{15,8,4,2,1},..

Crossrefs

Cf. A007755, A060611.

Sequence in context: A333266 A024624 A350162 * A027961 A348897 A349201

Adjacent sequences: A098193 A098194 A098195 * A098197 A098198 A098199

Keyword

nonn

Author

Labos Elemer, Sep 13 2004

Extensions

Corrected and extended by T. D. Noe, Sep 18 2008

Status

approved