A210002 Number of 2 X 2 matrices having all elements in {1,2,...,n} and determinant 4.

0, 0, 0, 4, 16, 26, 44, 62, 104, 122, 164, 198, 256, 298, 364, 390, 480, 538, 604, 670, 792, 834, 948, 1030, 1120, 1194, 1332, 1398, 1584, 1690, 1780, 1894, 2080, 2154, 2340, 2430, 2616, 2754, 2964, 3054, 3240, 3394, 3532, 3694, 4008, 4098

Offset

0,4

Comments

See A210000 for a guide to related sequences.

Links

Chai Wah Wu, Table of n, a(n) for n = 0..10000

Formula

a(n) = A209976(n) - 6*n - 3 for n >= 4. - David Radcliffe, Apr 29 2026

Mathematica

(See the Mathematica section at A209978.)

Crossrefs

Cf. A210000.

Sequence in context: A351979 A111350 A223221 * A105078 A050707 A134330

Adjacent sequences: A209999 A210000 A210001 * A210003 A210004 A210005

Keyword

nonn

Author

Clark Kimberling, Mar 16 2012

Status

approved