

A257796


Smallest value of the loop in which n ends, when iterating the map (A257588) which sends a number to absolute value of first digit squared minus second digit squared plus third digit squared etc.


6



1, 16, 9, 16, 9, 9, 0, 16, 9, 1, 0, 9, 16, 9, 9, 16, 48, 9, 16, 16, 9, 0, 9, 9, 9, 9, 9, 9, 0, 9, 16, 9, 0, 0, 16, 9, 16, 0, 9, 16, 9, 9, 0, 0, 9, 16, 0, 48, 0, 9, 9, 9, 16, 9, 0, 0, 9, 9, 0, 9, 16, 9, 9, 16, 0, 0, 16, 9, 9, 0
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OFFSET

1,2


COMMENTS

Six loops are possible. There are three loops of one.
21.0% of the numbers end up as zero.
Some numbers end up as a happy number (=1); density is 4.2%.
Some numbers end up as 48; density is 4.8%.
More numbers end up in a loop of two (16 and 35); density is 25.4%.
Most numbers end up in a loop of five (9, 81, 63, 27, 45, 9); density is 44.6%.


LINKS

Pieter Post, Table of n, a(n) for n = 1..999


EXAMPLE

a(17)=48 because abs(1^2  7^2) = 48 => abs(4^2  8^2) = 48.
a(34)=0 because abs(3^2  4^2) = 7 => 7^2 = 49 => abs(4^2  9^2) = 65 => abs(6^2  5^2) = 11 => abs(1^2  1^2) = 0.


CROSSREFS

Cf. A007770, A090425, A257588.
Sequence in context: A302683 A302518 A070567 * A070688 A281719 A103167
Adjacent sequences: A257793 A257794 A257795 * A257797 A257798 A257799


KEYWORD

nonn,base


AUTHOR

Pieter Post, May 09 2015


STATUS

approved



