A031351 5-multiplicative persistence: number of iterations of "multiply 5th powers of digits" needed to reach 0 or 1.

0, 4, 4, 2, 3, 3, 2, 3, 2, 1, 1, 4, 4, 2, 3, 3, 2, 3, 2, 1, 4, 2, 3, 3, 2, 4, 3, 2, 3, 1, 4, 3, 2, 4, 3, 3, 2, 3, 2, 1, 2, 3, 4, 2, 2, 3, 2, 3, 2, 1, 3, 2, 3, 2, 3, 2, 3, 2, 3, 1, 3, 4, 3, 3, 2, 2, 2, 2, 2, 1, 2, 3, 2, 2, 3, 2, 3, 2, 3, 1, 3, 2, 3, 3, 2, 2, 2, 2, 3, 1, 2, 3, 2, 2, 3, 2, 3, 3, 2

Offset

1,2

Comments

The maximum in the first 10,000 terms is 4. - Harvey P. Dale, Aug 26 2024

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Multiplicative Persistence

Mathematica

Table[Length[NestWhileList[(Times@@IntegerDigits[#])^5&, n, #>1&]], {n, 100}]-1 (* Harvey P. Dale, Aug 26 2024 *)

Crossrefs

Sequence in context: A276149 A146899 A317726 * A068923 A222295 A371706

Adjacent sequences: A031348 A031349 A031350 * A031352 A031353 A031354

Keyword

nonn,base

Author

Eric W. Weisstein

Status

approved