A006546 Number of elements (a b, c d) in SL(2,Z) with trace n and 0 <= a <= {b, c} <= d.

1, 2, 2, 3, 3, 4, 2, 8, 3, 4, 6, 8, 6, 8, 4, 10, 6, 14, 2, 18, 6, 4, 14, 18, 7, 12, 12, 22, 6, 8, 6, 31, 12, 12, 14, 28, 8, 28, 12, 18, 22, 8, 10, 26, 17, 28, 6, 50, 11, 36, 12, 18, 22, 28, 12, 44, 16, 20, 18, 52, 14, 28, 34, 28, 14, 28, 18, 72, 12

Offset

3,2

Links

Sean A. Irvine, Table of n, a(n) for n = 3..1000

Crossrefs

Sequence in context: A305788 A116473 A341151 * A031268 A237817 A306949

Adjacent sequences: A006543 A006544 A006545 * A006547 A006548 A006549

Keyword

nonn

Author

John Lewis (frc.mass.edu)

Extensions

More terms from Sean A. Irvine, May 07 2017

Status

approved