A061806 Numbers n such that the iterative cycle: n -> sum of digits of n^2 has only three distinct elements.

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

Links

Table of n, a(n) for n=1..60.

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

Cf. A007953, A004159, A061903 - A061910.

Sequence in context: A026678 A026869 A350662 * A306161 A119997 A010361

Adjacent sequences: A061803 A061804 A061805 * A061807 A061808 A061809

Keyword

nonn,base

Author

Asher Auel, May 17 2001

Status

approved