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A224782
Length of longest run of consecutive zeros in decimal representation of 2^n.
4
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1
OFFSET
0,54
COMMENTS
a(n) <= A027870(n);
a(A007377(n)) = 0;
a(A006889(n)) = n and a(m) <> n for m < A006889(n).
REFERENCES
Julian Havil, Impossible?: Surprising Solutions to Counterintuitive Conundrums, Princeton University Press 2008, chapter 15, p. 176ff
LINKS
PROG
(Haskell)
import Data.List (group)
a224782 n = a224782_list !! n
a224782_list = map (foldl h 0 . group . show) a000079_list where
h x zs@(z:_) = if z == '0' then max x $ length zs else x
CROSSREFS
Sequence in context: A360963 A231425 A136713 * A160322 A375667 A341644
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Apr 30 2013
STATUS
approved