A210001 Number of 2 X 2 matrices having all elements in {1,2,...,n} and determinant 3.

0, 0, 1, 7, 11, 23, 39, 59, 71, 115, 127, 163, 199, 243, 263, 339, 367, 427, 471, 539, 567, 683, 719, 803, 879, 955, 999, 1139, 1183, 1291, 1367, 1483, 1543, 1739, 1799, 1891, 1983, 2123, 2191, 2427, 2487, 2643, 2759, 2923, 2999, 3187, 3271, 3451, 3607, 3771, 3847

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) = A209975(n) - 4*n - 2 for n >= 3. - David Radcliffe, Apr 28 2026

Mathematica

(* See the Mathematica section at A209978. *)

Crossrefs

Cf. A210000, A209975, A209978.

Sequence in context: A082496 A239733 A265768 * A294074 A228227 A107133

Adjacent sequences: A209998 A209999 A210000 * A210002 A210003 A210004

Keyword

nonn

Author

Clark Kimberling, Mar 16 2012

Status

approved