A029913 Start with n; if prime, stop; repeatedly sum squares of prime factors (counted with multiplicity), until reach 16 or a prime; set a(n) = 0 if no limit exists.

2, 3, 17, 5, 13, 7, 17, 59, 29, 11, 17, 13, 53, 293, 16, 17, 59, 19

Offset

2,1

Links

Table of n, a(n) for n=2..19.

Example

9 -> 3^2 + 3^2 = 18 -> 4 + 9 + 9 = 22 -> 4 + 121 = 125 -> 25 + 25 + 25 = 75 -> 9 + 25 + 25 = 59, so a(9) = 59.

Crossrefs

Cf. A029914.

Sequence in context: A171990 A103898 A140383 * A073125 A171240 A078201

Adjacent sequences: A029910 A029911 A029912 * A029914 A029915 A029916

Keyword

nonn,more

Author

Dann Toliver

Extensions

More terms from Michel ten Voorde, Apr 12 2001

Incorrect extension reverted by Sean A. Irvine, Mar 08 2020

Status

approved