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

Author

Labos Elemer, Sep 13 2004

Keywords

• nonn

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]

Examples

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

Links

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

Crossrefs

Cf. A007755, A060611.

Extensions

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