login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A200146 Triangle read by rows: T(n, k) = mod(k^(n - 1), n), where 1 <= k < n. 1
1, 1, 1, 1, 0, 3, 1, 1, 1, 1, 1, 2, 3, 4, 5, 1, 1, 1, 1, 1, 1, 1, 0, 3, 0, 5, 0, 7, 1, 4, 0, 7, 7, 0, 4, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 8, 3, 4, 5, 0, 7, 8, 9, 4, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

2,6

COMMENTS

Per Fermat's Little theorem, if n is prime, then row n is all 1s. However, if n is composite, that does not necessarily guarantee that the first column 1 is the only one in the row.

LINKS

Table of n, a(n) for n=2..79.

EXAMPLE

The first seven rows are

1

1, 1

1, 0, 3

1, 1, 1, 1

1, 2, 3, 4, 5

1, 1, 1, 1, 1, 1

1, 0, 3, 0, 5, 0, 7

We observe that the tenth row consists of the numbers 1 to 9 in order. In base 10, the least significant digit of n^9 is the same as that of n.

MATHEMATICA

Column[Table[Mod[k^(n - 1), n], {n, 2, 13}, {k, n - 1}], Center] (* Nov 14 2011 *)

CROSSREFS

Cf. A089072, A066340 (Fermat's triangle).

Sequence in context: A030380 A066636 A137578 * A319095 A109390 A130046

Adjacent sequences:  A200143 A200144 A200145 * A200147 A200148 A200149

KEYWORD

nonn,easy,tabl

AUTHOR

Alonso del Arte, Nov 13 2011

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 22 18:55 EST 2019. Contains 329410 sequences. (Running on oeis4.)