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A061806
Numbers n such that the iterative cycle: n -> sum of digits of n^2 has only three distinct elements.
0
4, 5, 17, 26, 28, 32, 37, 40, 43, 44, 49, 50, 53, 62, 63, 64, 67, 73, 74, 76, 77, 82, 83, 86, 87, 88, 89, 91, 92, 93, 94, 97, 98, 107, 109, 113, 114, 116, 117, 118, 122, 124, 125, 126, 127, 128, 133, 137, 141, 143, 149, 154, 157, 158, 161, 164, 166, 167, 169, 170
OFFSET
1,1
EXAMPLE
4 -> 1+6 = 7 -> 4+9 = 13 -> 1+6+9 = 16 -> 2+5+6 = 13, thus {7,13,16} are the only distinct elements of the iterative cycle of 4.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Asher Auel, May 17 2001
STATUS
approved