

A196096


Occurrences of '11' in base 3 expansion of n.


2



0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 2, 3, 2, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1
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OFFSET

0,14


COMMENTS

Occurrences of '11' in A007089(n). This is to base 3 and A007089 as A014081 is to base 2 A007088.
First occurrence of k>0 = 4, 13, 40, 121, 364, ..., = A003462(k). (* Robert G. Wilson v, Sep 27 2011 *)


LINKS

T. D. Noe, Table of n, a(n) for n = 0..1000


EXAMPLE

a(4) = 1 because 4 in base 3 is "11" which has one instance of "11".
a(13) = 2 because the number 13 in base 3 is "111" which has two substrings of "11".


MAPLE

A196096 := proc(n)
local a, dgs3 ;
a := 0 ;
dgs3 := convert(n, base, 3) ;
for i from 1 to nops(dgs3)1 do
if op(i, dgs3)=1 and op(i+1, dgs3)=1 then
a := a+1 ;
end if;
end do;
a ;
end proc:
seq(A196096(n), n=0..80) ; # R. J. Mathar, Sep 28 2011


MATHEMATICA

f[n_] := Count[ Partition[ IntegerDigits[ n, 3], 2, 1], {1, 1}]; Array[f, 100, 0] (* Robert G. Wilson v, Sep 27 2011 *)


CROSSREFS

Cf. A007089, A014081.
Sequence in context: A037878 A107652 A186734 * A249344 A067150 A289922
Adjacent sequences: A196093 A196094 A196095 * A196097 A196098 A196099


KEYWORD

easy,nonn


AUTHOR

Jonathan Vos Post, Sep 27 2011


STATUS

approved



