login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A037042 2-White numbers (take power 2, sum 2-digit groups to get same number). 15
0, 1, 45, 55, 99 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

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

REFERENCES

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

LINKS

Table of n, a(n) for n=1..5.

D. E. Iannucci, The Kaprekar numbers, J. Integer Sequences, Vol. 3, 2000, #1.2.

Index entries for Colombian or self numbers and related sequences

EXAMPLE

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

CROSSREFS

Sequence in context: A167328 A116247 A168108 * A119208 A068812 A119071

Adjacent sequences:  A037039 A037040 A037041 * A037043 A037044 A037045

KEYWORD

full,nonn,fini,base

AUTHOR

Erich Friedman

EXTENSIONS

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

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 16 08:36 EDT 2019. Contains 327091 sequences. (Running on oeis4.)