A061907 The iterative cycle: n -> sum of digits of n^2 has only four distinct elements.

2, 11, 20, 101, 110, 134, 136, 163, 172, 197, 200, 217, 233, 242, 244, 262, 278, 287, 296, 298, 307, 313, 314, 316, 343, 359, 386, 397, 406, 413, 422, 424, 431, 433, 442, 458, 467, 469, 476, 478, 487, 514, 523, 541, 577, 583, 586, 593, 604, 613, 614, 622

Offset: 1

Author

Asher Auel, May 17 2001

Keywords

• nonn
• base

Examples

			a(2) = 4 since 2 -> 4 -> 1+6 = 7 -> 4+9 = 13 -> 1+6+9 = 16 -> 2+5+6 = 13, thus {4,7,13,16} are the distinct elements of the iterative cycle of 2.
		

Crossrefs

Cf. A007953, A004159, A061903 - A061910.