

A004647


Powers of 2 written in base 8.


1



1, 2, 4, 10, 20, 40, 100, 200, 400, 1000, 2000, 4000, 10000, 20000, 40000, 100000, 200000, 400000, 1000000, 2000000, 4000000, 10000000, 20000000, 40000000, 100000000, 200000000, 400000000, 1000000000
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OFFSET

0,2


COMMENTS

Or, numbers of form 10^n, 2*10^n, 4*10^n.
Or, numbers n such that the digits of n^3 are decreasing.  Dmitry Kamenetsky, Jun 15 2006


REFERENCES

D. Panario, M. Sahin, Q. Wang, A family of Fibonaccilike conditional sequences, INTEGERS, Vol. 13, 2013, #A78.


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Thomas Harriot, Manuscript 6782, p. 1, c. 1599.


FORMULA

a(0)=1, a(1)=2, a(2)=4, a(n)=10*a(n3).  Harvey P. Dale, Aug 16 2012


MATHEMATICA

Table[FromDigits[IntegerDigits[2^n, 8]], {n, 0, 30}] (* or *) LinearRecurrence[ {0, 0, 10}, {1, 2, 4}, 30] (* Harvey P. Dale, Aug 16 2012 *)


PROG

(PARI) a(n)=2^(n%3)*10^(n\3) \\ Charles R Greathouse IV, Oct 22 2014


CROSSREFS

Sequence in context: A127392 A189585 A239346 * A236572 A167030 A026644
Adjacent sequences: A004644 A004645 A004646 * A004648 A004649 A004650


KEYWORD

nonn,base,easy


AUTHOR

N. J. A. Sloane.


STATUS

approved



