login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A073966 Number of strings of length n over Z_5 with trace 1 and subtrace 0. 7

%I #26 May 03 2019 07:17:27

%S 1,2,6,20,125,625,3150,15500,78000,390625,1955625,9768750,48831250,

%T 244125000,1220703125,6103515625,30517656250,152587500000,

%U 762939062500,3814697265625,19073494140625,95367441406250,476837167968750,2384185742187500,11920928955078125

%N Number of strings of length n over Z_5 with trace 1 and subtrace 0.

%C Same as the number of strings of length n over Z_5 with: trace 2 and subtrace 0, trace 3 and subtrace 0, or trace 4 and subtrace 0.

%C Same as the number of strings of length n over GF(5) with: trace 2 and subtrace 0, or trace 3 and subtrace 0.

%H Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>

%H F. Ruskey, <a href="http://combos.org/TSstringZ5">Strings over Z_5 with given trace and subtrace</a>

%H F. Ruskey, <a href="http://combos.org/TSstringF5">Strings over GF(5) with given trace and subtrace</a>

%F a(n; t, s) = a(n-1; t, s) + a(n-1; t+4, s+4t+1) + a(n-1; t+3, s+3t+4) + a(n-1; t+2, s+2t+4) + a(n-1; t+1, s+t+1).

%F Empirical g.f.: -x*(25*x^6 -50*x^5 +15*x^4 +20*x^3 -21*x^2 +8*x -1) / ((5*x -1)*(5*x^2 -1)*(25*x^4 -25*x^3 +15*x^2 -5*x +1)). - _Colin Barker_, Nov 25 2014

%Y Cf. A073963, A073964, A073965, A073967, A073968, A073969, A073970.

%K easy,nonn

%O 1,2

%A _Frank Ruskey_, Nate Kube, Aug 15 2002

%E Terms a(11) onward from _Max Alekseyev_, Apr 09 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)