A020479 Number of noninvertible 2 X 2 matrices over Z/nZ (determinant is a divisor of 0).

10, 33, 160, 145, 1008, 385, 2560, 2673, 7120, 1441, 16128, 2353, 26320, 27585, 40960, 5185, 81648, 7201, 113920, 97713, 155056, 12673, 258048, 90625, 299728, 216513, 421120, 25201, 671760, 30721, 655360, 552321, 866320, 532945, 1306368, 51985

Offset

2,1

Links

Table of n, a(n) for n=2..37.

Formula

a(n) seems to be divisible by n. - Ralf Stephan, Sep 01 2003

a(n)=n^4-A000252(n). - T. D. Noe, Jan 16 2006

Crossrefs

Sequence in context: A094170 A004638 A211033 * A219818 A264251 A140866

Adjacent sequences: A020476 A020477 A020478 * A020480 A020481 A020482

Keyword

nonn

Author

David W. Wilson

Status

approved