OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (7,-6).
FORMULA
a(n) = (6^n-1)*4/5.
G.f.: 4*x/((1-x)*(1-6*x)). - Vincenzo Librandi, Sep 26 2015
EXAMPLE
Base 6.........decimal
4....................4
44..................28
444................172
4444..............1036
44444.............6220
444444...........37324
4444444.........223948
44444444.......1343692
444444444......8062156
4444444444....48372940
etc.
MAPLE
seq((6^n-1)*4/5, n=1..24);
MATHEMATICA
4 (6^Range[20]-1)/5 (* Harvey P. Dale, Mar 12 2011 *)
Rest[CoefficientList[Series[4 x/((1 - x) (1 - 6 x)), {x, 0, 30}], x]] (* Vincenzo Librandi, Sep 26 2015 *)
Table[FromDigits[PadRight[{}, n, 4], 6], {n, 30}] (* or *) LinearRecurrence[{7, -6}, {4, 28}, 30] (* Harvey P. Dale, Jan 02 2023 *)
PROG
(Magma) [(6^n-1)*4/5: n in [1.. 35]]; // Vincenzo Librandi, Sep 26 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zerinvary Lajos, Jan 31 2007
EXTENSIONS
Edited by N. J. A. Sloane, Feb 02 2007
More terms from Vincenzo Librandi, Sep 26 2015
STATUS
approved