A215883 - OEIS

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A215883

When written in base 4, n ends in a(n) consecutive nonzero digits.

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

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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.

LINKS

Table of n, a(n) for n=0..86.

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

Adjacent sequences: A215880 A215881 A215882 * A215884 A215885 A215886

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Aug 25 2012

STATUS

approved