A037042 2-White numbers (take power 2, sum 2-digit groups to get same number).

0, 1, 45, 55, 99

Offset: 1

Author

Erich Friedman

Keywords

• full
• nonn
• fini
• base

Comments

Also, apart from initial 0, the full list of 2-Kaprekar numbers.

Examples

			45 is a 2-White number since 45^2 = 2025 and 20 + 25 = 45.
		

References

• Italo Ghersi, Matematica dilettevole e curiosa, p. 190, Hoepli, Milano, 1967. [Vincenzo Librandi, Apr 22 2010]

Links

• D. E. Iannucci, The Kaprekar numbers, J. Integer Sequences, Vol. 3, 2000, #1.2.
• Index entries for Colombian or self numbers and related sequences

Extensions

Offset set to 1 by Paolo P. Lava, Jul 12 2016