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!)
A095026 Lower triangle T(j,k) read by rows, where T(j,k) is the number of occurrences of the digit k-1 as least significant digit in the base-j multiplication table. 1
1, 3, 1, 5, 2, 2, 8, 2, 4, 2, 9, 4, 4, 4, 4, 15, 2, 6, 5, 6, 2, 13, 6, 6, 6, 6, 6, 6, 20, 4, 8, 4, 12, 4, 8, 4, 21, 6, 6, 12, 6, 6, 12, 6, 6, 27, 4, 12, 4, 12, 9, 12, 4, 12, 4, 21, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 40, 4, 8, 10, 16, 4, 20, 4, 16, 10, 8, 4, 25, 12, 12, 12, 12, 12, 12, 12 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Sum_{k=1..j} T(j,k) = j^2.

Assumes a suitable continuation of the representation of digits in bases 11, 12 (9,A,B,..)

LINKS

Table of n, a(n) for n=1..86.

David Book, The Multiplying Digits Problem.

EXAMPLE

a(2)=T(2,1)=3 because 3 of the 4 possible combinations of last digits in the

product of two binary numbers produce 0 as last digit of the result. a(3)=T(2,2)=1 because only ...1 * ...1 gives a result with last digit=1.

T(10,k)={27,4,12,4,12,9,12,4,12,4} gives the probability in percent (j^2=100) to get {0,1,2,...,9} as last decimal digit in the decimal representation of the product of two arbitrary integers.

CROSSREFS

The first column T(n, 1)=A018804(n).

Sequence in context: A233940 A134033 A185051 * A184997 A094367 A092368

Adjacent sequences:  A095023 A095024 A095025 * A095027 A095028 A095029

KEYWORD

nonn,tabl,base

AUTHOR

Hugo Pfoertner, Jun 02 2004

EXTENSIONS

More terms from David Wasserman, Jun 03 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 May 18 22:37 EDT 2022. Contains 353826 sequences. (Running on oeis4.)