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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 28 18:04 EDT 2021. Contains 347716 sequences. (Running on oeis4.)