A004655 Powers of 2 written in base 16.
1, 2, 4, 8, 10, 20, 40, 80, 100, 200, 400, 800, 1000, 2000, 4000, 8000, 10000, 20000, 40000, 80000, 100000, 200000, 400000, 800000, 1000000, 2000000, 4000000, 8000000, 10000000, 20000000, 40000000, 80000000
Offset: 0
Links
- G. C. Greubel, Table of n, a(n) for n = 0..2500
- Index entries for linear recurrences with constant coefficients, signature (0,0,0,10).
Crossrefs
Programs
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Magma
[Seqint(Intseq(2^n, 16)): n in [0..30]]; // G. C. Greubel, Sep 10 2018
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Mathematica
Table[FromDigits[IntegerDigits[2^n, 16]], {n, 50}] (* G. C. Greubel, Sep 11 2018 *) -
PARI
apply( a(n)=2^(n%4)*10^(n\4), [0..30]) \\ M. F. Hasler, Jun 22 2018
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Python
def A004655(n): return 10**(n>>2)<<(n&3) # Chai Wah Wu, Jan 27 2023
Formula
a(n) = 2^(n mod 4)*10^floor(n/4). - M. F. Hasler, Jun 22 2018
From Chai Wah Wu, Sep 03 2020: (Start)
a(n) = 10*a(n-4) for n > 3.
G.f.: -(2*x + 1)*(4*x^2 + 1)/(10*x^4 - 1). (End)
Comments