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A061905 The iterative cycle: n -> sum of digits of n^2 has only two distinct elements. 0
7, 8, 13, 14, 16, 19, 22, 23, 24, 25, 27, 29, 31, 33, 34, 35, 36, 38, 41, 42, 46, 47, 52, 54, 55, 56, 57, 58, 59, 61, 65, 66, 68, 69, 70, 71, 72, 75, 78, 79, 80, 81, 84, 85, 95, 96, 99, 103, 104, 106, 108, 112, 115, 119, 121, 123, 129, 130, 131, 132, 135, 138, 139, 140 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It seems that {10,1}, {13,16} and {9,18} are the only iterative cycles with 2 distinct elements.

LINKS

Table of n, a(n) for n=1..64.

EXAMPLE

7 -> 4+9 = 13 -> 1+6+9 = 16 -> 2+5+6 = 13, thus only {13,16} are contained in the iterative cycle of 7. 24 -> 5+7+6 = 18 -> 3+2+4 = 9 -> 8+1 = 9, thus {18,9} are the only elements of the iterative cycle of 24.

CROSSREFS

Cf. A007953, A004159, A061903 - A061910.

Sequence in context: A065729 A156605 A343298 * A308887 A308833 A025156

Adjacent sequences:  A061902 A061903 A061904 * A061906 A061907 A061908

KEYWORD

nonn,base

AUTHOR

Asher Auel (asher.auel(AT)reed.edu), May 17 2001

STATUS

approved

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Last modified June 21 03:51 EDT 2021. Contains 345354 sequences. (Running on oeis4.)