OFFSET
1,1
COMMENTS
Related to a problem posed by Google and discussed on the MathWorld link.
This is the complete list of all 13 positive numbers n such that n is equal to the number of 2's in the decimal digits of all numbers <= n. - Daniel Hirschberg (dan(AT)ics.uci.edu), May 05 2007
LINKS
Tanya Khovanova and Gregory Marton, Archive Labeling Sequences, arXiv:2305.10357 [math.HO], 2023.
Mathworld, Problem 17 of Google Labs Aptitude Test Partially Answered, MathWorld Headline News, October 13 2004.
EXAMPLE
a(1) = 28263827 since writing out all numbers from 0 to 28263827 requires that 28263827 2's be used and since 28263827 is the first such positive integer.
a(4) = 500000000 because the number of 2's in the decimal digits of the numbers from 1 to 500000000 is 500000000 and this is the 4th such number.
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Ryan Propper, Dec 10 2004
EXTENSIONS
More terms from Daniel Hirschberg (dan(AT)ics.uci.edu), May 05 2007
STATUS
approved