OFFSET
0,2
COMMENTS
Also the second differences of A001047.
Equals sum of "terms added" to current row of the triangle version of A038573 to get the next row. a(3) = 32 sum of (3, 7, 7, 15) = terms appended to row 2 of the triangle in A038573. - Gary W. Adamson, Jun 04 2009
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (5,-6).
FORMULA
a(n) = 5*a(n-1) - 6*a(n-2) + C(2,2-n), n>1, with a(0)=1, a(1)=3, where C(2, 2-n)=1 for n=2 and =0 for n>2.
From Paul Barry, Jun 26 2003: (Start)
Binomial transform of A000975(n+1).
G.f.: (1-x)^2/((1-2*x)*(1-3*x)).
a(n) = 4*3^n/3 + 0^n/6 - 2^n/2. (End)
a(n) = Sum_{k=0..n+1} binomial(n+1, k) * Sum_{j=0..floor(k/2)} A001045(k-2*j). - Paul Barry, Apr 17 2005
E.g.f.: (1 - 3*exp(2*x) + 8*exp(3*x))/6. - G. C. Greubel, May 16 2019
MATHEMATICA
CoefficientList[Series[(1-x)^2/((1-2x)(1-3x)), {x, 0, 30}], x] (* Harvey P. Dale, Apr 22 2011 *)
PROG
(Magma) [4*3^n/3+0^n/6-2^n/2: n in [0..30]]; // Vincenzo Librandi, Jul 17 2011
(PARI) vector(30, n, n--; 4*3^(n-1) +(0^n -3*2^n)/6) \\ G. C. Greubel, May 16 2019
(Sage) [4*3^(n-1) +(0^n -3*2^n)/6 for n in (0..30)] # G. C. Greubel, May 16 2019
(GAP) List([0..30], n-> 4*3^(n-1) +(0^n -3*2^n)/6) # G. C. Greubel, May 16 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, Jan 18 2000
STATUS
approved