A073974 Number of strings of length n over Z_6 with trace 0 and subtrace 3.

0, 1, 9, 54, 210, 1008, 6300, 40824, 262440, 1679616, 10478160, 62868960, 369476640, 2176782336, 12958657344, 77751944064, 468205557120, 2820249944064, 16957996040448, 101758315958784, 609954817881600, 3656158440062976, 21926486787222528, 131558920723335168

Offset

1,3

Links

Table of n, a(n) for n=1..24.

Max Alekseyev, PARI/GP scripts for miscellaneous math problems

F. Ruskey Strings over Z_6 with given trace and subtrace

Formula

a(n; t, s) = a(n-1; t, s) + a(n-1; t+5, s+5t+1) + a(n-1; t+4, s+4t+4) + a(n-1; t+3, s+3t+3) + a(n-1; t+2, s+2t+2) + a(n-1; t+1, s+t+1) where t is the trace and s is the subtrace.

Crossrefs

Cf. A073971 - A073994.

Sequence in context: A152994 A034719 A013567 * A223927 A307045 A035927

Adjacent sequences: A073971 A073972 A073973 * A073975 A073976 A073977

Keyword

easy,nonn

Author

Frank Ruskey and Nate Kube, Aug 16 2002

Extensions

Terms a(11) onward from Max Alekseyev, Apr 09 2013

Status

approved