A073973 Number of strings of length n over Z_6 with trace 0 and subtrace 2.

0, 2, 6, 24, 180, 1440, 9072, 50544, 286416, 1658880, 9722592, 58335552, 356638464, 2179768320, 13180786560, 79012495872, 472093588224, 2821539889152, 16894457846784, 101356447675392, 608733733690368, 3656096522698752, 21947538146863104, 131685228881178624

Offset

1,2

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, A073974, A073975, A073976, A073977, A073978, A073979, A073980, A073981, A073982, A073983.

Cf. A073984, A073985, A073986, A073987, A073988, A073989, A073990, A073991, A073992, A073993, A073994.

Sequence in context: A012711 A356579 A352059 * A356575 A347895 A355284

Adjacent sequences: A073970 A073971 A073972 * A073974 A073975 A073976

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