A209977 Number of 2 X 2 matrices having all elements in {0,1,...,n} and determinant 5.

0, 0, 0, 3, 9, 45, 53, 77, 93, 117, 153, 193, 209, 257, 281, 353, 385, 449, 473, 545, 617, 665, 705, 793, 825, 985, 1033, 1105, 1153, 1265, 1337, 1457, 1521, 1601, 1665, 1881, 1929, 2073, 2145, 2241, 2385, 2545, 2593, 2761, 2841, 3057, 3145

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) = 4*A002088(n) + 20*A002088(floor(n/5)) - 15 for n >= 4. - David Radcliffe, Apr 27 2026

Mathematica

(See the Mathematica section at A210000.)

Crossrefs

Cf. A210000, A002088.

Sequence in context: A058106 A021103 A222662 * A001902 A224085 A352797

Adjacent sequences: A209974 A209975 A209976 * A209978 A209979 A209980

Keyword

nonn,easy

Author

Clark Kimberling, Mar 16 2012

Status

approved