A073990 Number of strings of length n over Z_6 with trace 3 and subtrace 1.

0, 0, 0, 24, 300, 1800, 9072, 48384, 272160, 1594080, 9722592, 60217344, 367960320, 2207761920, 13144674816, 78328332288, 468419708160, 2810518248960, 16894457846784, 101565116448768, 609985806796800, 3659790885120000, 21947538146863104, 131620960833896448

Offset

1,4

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, A073988, A073989, A073991, A073992, A073993, A073994.

Sequence in context: A161931 A162366 A153782 * A056290 A056285 A162686

Adjacent sequences: A073987 A073988 A073989 * A073991 A073992 A073993

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