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A305930 Number of digits '0' in 3^n (in base 10). 2
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 3, 2, 0, 0, 1, 0, 0, 0, 1, 2, 0, 2, 2, 0, 4, 2, 3, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 3, 1, 2, 1, 2, 7, 6, 2, 5, 2, 4, 2, 2, 2, 1, 2, 4, 4, 3, 0, 2, 4, 2, 1, 1, 4, 3, 5, 4, 5, 4, 5, 3, 3, 2, 6, 6, 5, 3, 4, 5, 3, 5, 5, 2, 6, 6, 2, 6, 4, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,22

LINKS

Table of n, a(n) for n=0..99.

FORMULA

a(n) = A055641(A000244(n)).

a(A030700(n)) = 0; a(A305934(n)) = 1; a(A305931(n)) >= 1; a(A305933(n,k)) = n.

EXAMPLE

3^10 = 59049 is the smallest power of 3 having a digit 0, so a(10) = 1 is the first nonzero term.

MATHEMATICA

Table[ Count[ IntegerDigits[3^n], 0], {n, 0, 100} ]

DigitCount[3^Range[0, 110], 10, 0]

PROG

(PARI) apply( A305930(n)=#select(d->!d, digits(3^n)), [0..99])

(Haskell) a305930 = a055641 . a000244

CROSSREFS

Cf. A027870 (analog for 2^k), A030700 (indices of zeros).

Cf. A063555: index of first appearence of n in this sequence.

Cf. A305933: table with n in row a(n).

Sequence in context: A033909 A292240 A324881 * A206590 A206825 A336551

Adjacent sequences:  A305927 A305928 A305929 * A305931 A305932 A305933

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Jun 22 2018

STATUS

approved

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Last modified November 30 13:47 EST 2021. Contains 349420 sequences. (Running on oeis4.)