OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (6,-8).
FORMULA
a(n) = 4*a(n-1) + 3*2^(n-1).
a(n) = (5/2)*4^n - (3/2)*2^n.
G.f.: (1+x)/((1-2*x)*(1-4*x)). - Klaus Brockhaus, Nov 26 2009
a(n) = 6*a(n-1) - 8*a(n-2), a(0)=1, a(1)=7. - Harvey P. Dale, Nov 12 2012
E.g.f.: exp(2*x)*(5*exp(2*x) - 3)/2. - G. C. Greubel, Nov 23 2021
MATHEMATICA
RecurrenceTable[{a[0]==1, a[n]==4a[n-1]+3*2^(n-1)}, a, {n, 30}] (* or *) LinearRecurrence[{6, -8}, {1, 7}, 30] (* Harvey P. Dale, Nov 12 2012 *)
CoefficientList[Series[(1+x)/((1-2x)(1-4x)), {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
PROG
(Magma) binomtf:=func< V | [ &+[ Binomial(i-1, k-1)*V[k]: k in [1..i] ]: i in [1..#V] ] >; binomtf(binomtf(binomtf(&cat[ [1, 4]: n in [1..12] ]))); // Klaus Brockhaus, Nov 26 2009
(Sage) [2^(n-1)*(5*2^n -3) for n in (0..30)] # G. C. Greubel, Nov 23 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 03 2003
EXTENSIONS
Definition corrected, edited by Klaus Brockhaus, Nov 26 2009
STATUS
approved