A073988 Number of strings of length n over Z_6 with trace 2 and subtrace 5.

0, 0, 9, 72, 300, 1296, 7056, 42336, 262440, 1658880, 10349856, 62355744, 367960320, 2173796352, 12958657344, 77787495936, 468419708160, 2821109907456, 16960580969472, 101763485816832, 609954817881600, 3656096522698752, 21926115464435712, 131557435432187904

Offset

1,3

Comments

Same as the number of strings of length n over Z_6 with trace 4 and subtrace 5.

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, A073972, A073973, A073974, A073975, A073976, A073977, A073978, A073979, A073980, A073981, A073982, A073983, A073984, A073985, A073986, A073987, A073989, A073990, A073991, A073992, A073993, A073994.

Sequence in context: A244728 A069978 A070823 * A005778 A288351 A319892

Adjacent sequences: A073985 A073986 A073987 * A073989 A073990 A073991

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