A094658 Smallest number which requires n iterations to reach a prime when iterating x + sum of squares of digits of x.

1, 48, 28, 6, 9, 4, 33, 30, 22, 54, 8, 26, 21, 112, 92, 80, 27, 64, 972, 878, 805, 669, 576, 484, 377, 291, 253, 1629, 6591, 6474, 6289, 6167, 5976, 5853, 5697, 5558, 5456, 5492, 5379, 5282, 5183, 4986, 4936, 4790, 4666, 4489, 4384, 4284, 4416, 6183, 5992, 21693

Offset

1,2

Links

Table of n, a(n) for n=1..52.

Example

a(3)=28 because 28 takes 3 iterations to reach a prime: 28 -> 96 -> 213 -> 227.

Crossrefs

Sequence in context: A033368 A128380 A298451 * A136455 A085517 A299525

Adjacent sequences: A094655 A094656 A094657 * A094659 A094660 A094661

Keyword

base,nonn

Author

Jason Earls, Jun 14 2004

Status

approved