|
Search: id:A113917
|
|
|
| A113917 |
|
Maximal element of Image^inf({ 2 }) under repeated base-n zero-split squaring. |
|
+0
2
|
|
| 2, 1849, 2, 55834574872, 71936956422890357877389, 243595882728074946109199629661893196422198513949733, 4
(list; graph; listen)
|
|
|
OFFSET
|
2,1
|
|
|
COMMENT
|
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
|
|
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: A080642 A108331 A162554 this_sequence A160299 A125635 A124361
Adjacent sequences: A113914 A113915 A113916 this_sequence A113918 A113919 A113920
|
|
KEYWORD
|
nonn,hard
|
|
AUTHOR
|
Hugo van der Sanden (hv(AT)crypt.org) extending a suggestion from David W. Wilson, Jan 31 2006
|
|
|
Search completed in 0.002 seconds
|
