login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097327 Least positive integer m such that m*n has greater decimal digit length than n. 2
10, 5, 4, 3, 2, 2, 2, 2, 2, 10, 10, 9, 8, 8, 7, 7, 6, 6, 6, 5, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 10, 10, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For any positive base B >= 2 the corresponding sequence contains only terms from 2 to B inclusive so the corresponding sequence for binary is all 2s (A007395).

LINKS

Michael S. Branicky, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A097326(n) + 1.

a(n) = ceiling(10^A055642(n)/n). - Michael S. Branicky, Oct 05 2021

EXAMPLE

a(12) = 9 since 12 has two decimal digits and 9*12 = 108 has three (but 8*12 = 96 has only two).

PROG

(Python)

def a(n): return (10**len(str(n))-1)//n + 1

print([a(n) for n in range(1, 103)]) # Michael S. Branicky, Oct 05 2021

(PARI) a(n) = my(m=1, sn=#Str(n)); while (#Str(m*n) <= sn, m++); m; \\ Michel Marcus, Oct 05 2021

CROSSREFS

Cf. A089186 (analog for decimal m+n), A080079 (analog for binary m+n), A097326.

Cf. A055642.

Sequence in context: A134167 A080461 A066578 * A226583 A007272 A061280

Adjacent sequences: A097324 A097325 A097326 * A097328 A097329 A097330

KEYWORD

base,easy,nonn

AUTHOR

Rick L. Shepherd, Aug 04 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 5 23:07 EST 2023. Contains 360091 sequences. (Running on oeis4.)