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A215883
When written in base 4, n ends in a(n) consecutive nonzero digits.
3
0, 1, 1, 1, 0, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 0, 1, 1, 1, 0, 3, 3, 3, 0, 3, 3, 3, 0, 3, 3, 3, 0, 1, 1, 1, 0, 3, 3, 3, 0, 3, 3, 3, 0, 3, 3, 3, 0, 1, 1, 1, 0, 3, 3, 3, 0, 3, 3, 3, 0, 3, 3, 3, 0, 1, 1, 1, 0, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 0, 1, 1, 1, 0, 4, 4
OFFSET
0,6
COMMENTS
Sequences A215879, A215884 and A215887 are the base 3, 5 and 10 analog, while the base 2 analog of this sequence coincides (up to a shift in the index) with the 2-adic valuation A007814, see comments there.
FORMULA
a(4^(t+1)*k+m) = t for 4^t > m > 4^(t-1).
EXAMPLE
The numbers 0,1,2,3,4,5,6,7 are written in base 4 as 0,1,2,3,10,11,12,13 and thus end in a(0..7)=0,1,1,1,0,2,2,2 nonzero digits.
PROG
(PARI) a(n, b=4)=n=divrem(n, b); for(c=0, 9e9, n[2]||return(c); n=divrem(n[1], b))
(PARI) a(n)=my(k); while(n%4, n>>=2; k++); k \\ Charles R Greathouse IV, Sep 26 2013
CROSSREFS
Sequence in context: A002100 A108352 A346149 * A277024 A317528 A246793
KEYWORD
nonn,base
AUTHOR
M. F. Hasler, Aug 25 2012
STATUS
approved