A215884 - OEIS

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A215884

Written in base 5, n ends in a(n) consecutive nonzero digits.

0, 1, 1, 1, 1, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 0, 1, 1, 1, 1, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 1, 1, 1, 1, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 1, 1, 1, 1, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 3, 3, 3, 3, 0, 1, 1, 1, 1, 0, 3

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OFFSET

0,7

COMMENTS

Sequences A215879, A215883 and A215887 are the base 3, 4 and 10 analogs, while the base 2 analog of this sequence coincides (up to a shift in the index) with the 2-adic valuation A007814, cf. comments there.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 0..1000

EXAMPLE

The numbers 24,...,31 are written in base 5 as 44,100,101,102,103,104,110,111 and thus end in a string of a(24..31)=2,0,1,1,1,1,0,3 nonzero digits.

MATHEMATICA

cnzd[n_]:=Module[{c=Split[If[#>0, 1, 0]&/@IntegerDigits[n, 5]]}, If[FreeQ[ c[[-1]], 0], Total[c[[-1]]], 0]]; Array[cnzd, 120, 0] (* Harvey P. Dale, Jan 03 2023 *)

PROG

(PARI) a(n, b=5)=n=divrem(n, b); for(c=0, 9e9, n[2]||return(c); n=divrem(n[1], b))

(PARI) a(n)=my(k); while(n%5, n\=5; k++); k \\ Charles R Greathouse IV, Sep 26 2013

CROSSREFS

Sequence in context: A053398 A065833 A245476 * A305029 A097033 A268686

Adjacent sequences: A215881 A215882 A215883 * A215885 A215886 A215887

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Aug 25 2012

STATUS

approved