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A164046
A001445 written in base 2.
1
11, 101, 1010, 10010, 100100, 1000100, 10001000, 100001000, 1000010000, 10000010000, 100000100000, 1000000100000, 10000001000000, 100000001000000, 1000000010000000, 10000000010000000, 100000000100000000, 1000000000100000000, 10000000001000000000
OFFSET
1,1
COMMENTS
The digit pattern is: one digit 1, A004526(n) times 0, one digit 1, and A004526(n-1) times 0.
FORMULA
a(n) = 2^n + 2^A004526(n-1) = A007088(A001445(n)).
From Chai Wah Wu, Sep 10 2020: (Start)
a(n) = 10*a(n-1) + 10*a(n-2) - 100*a(n-3) for n > 3.
G.f.: x*(-110*x^2 - 9*x + 11)/((10*x - 1)*(10*x^2 - 1)). (End)
MATHEMATICA
Table[IntegerString[(2^n + 2^(Floor[n/2]))/2, 2], {n, 2, 50}] (* G. C. Greubel, Sep 08 2017 *)
CROSSREFS
Sequence in context: A147759 A147757 A089183 * A284235 A284299 A284347
KEYWORD
nonn,base,easy
AUTHOR
Jaroslav Krizek, Aug 08 2009
EXTENSIONS
Extended by R. J. Mathar, Aug 11 2009
STATUS
approved