A169821 a(n) = n*n in carryless arithmetic mod 9 in base 10.

0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 100, 121, 144, 160, 187, 117, 130, 154, 171, 100, 400, 441, 484, 430, 477, 427, 460, 414, 451, 400, 0, 61, 34, 0, 67, 37, 0, 64, 31, 0, 700, 781, 774, 760, 757, 747, 730, 724, 711, 700, 700, 711, 724, 730, 747, 757, 760, 774, 781, 700, 0, 31, 64

Offset

0,3

Comments

Addition and multiplication are the same as in school, that is, done in base 10, except that there are no carries and individual digits are added or multiplied mod 9.

Links

Table of n, a(n) for n=0..62.

Index entries for sequences related to carryless arithmetic

Example

13*13 = 160:
..13
..13
----
..30
.13.
----
.160
----

Crossrefs

Cf. A010878, A169908. See A170990 for a better version.

Sequence in context: A117543 A242970 A070433 * A170990 A013666 A196533

Adjacent sequences: A169818 A169819 A169820 * A169822 A169823 A169824

Keyword

nonn,base

Author

David Applegate, Marc LeBrun and N. J. A. Sloane, Jul 11 2010

Status

approved