login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A113917 Maximal element of Image^inf({ 2 }) under repeated base-n zero-split squaring. 2
2, 1849, 2, 266423227914725931, 3100840870711697060720215047, 845486430620513036335402848567278325780455810752216401, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
COMMENTS
Define f_b(x) to be the set of base b numbers left after splitting x^2 at its zero digits and Image_b(S) = union_{x in S}{ { x } union f_b(S) }, then a(n) = max(Image_n^inf({ 2 }))
Conjecture: a(n) is finite for all n.
LINKS
Hugo van der Sanden, Perl and C implementations, Feb 03 2015
EXAMPLE
f_10(29648) = { 4, 39, 879 } since 29648^2 = 879003904;
a(8) = 4 since Image_8({ 2 }) = { 2, 4 } and f_8({ 2, 4 }) = { 2, 4 } and max({ 2, 4 }) is 4.
CROSSREFS
Cf. A113918.
Sequence in context: A263076 A162554 A167840 * A259487 A329663 A069793
KEYWORD
nonn,hard
AUTHOR
Hugo van der Sanden extending a suggestion from David W. Wilson, Jan 31 2006
EXTENSIONS
Corrected by Hugo van der Sanden, Feb 03 2015
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 23 17:43 EST 2024. Contains 370283 sequences. (Running on oeis4.)