OFFSET
0,3
COMMENTS
Binomial transform of A081200.
Conjecture (verified up to a(8)): Number of collinear 6-tuples of points in a 6 X 6 X 6 X... n-dimensional cubic grid. [R. H. Hardin, May 23 2010]
From Wolfdieter Lang, Jul 17 2017: (Start)
For a combinatorial interpretation of a(n) with special 8-letter words of length n see the comment in A081200 on the 7-letter analog.
The binomial transform of {a(n)}_{n >= 0} is A081202, the 9-letter analog.
(End)
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (14,-48).
FORMULA
a(n) = 14*a(n-1) - 48*a(n-2) with n>1, a(0)=0, a(1)=1.
G.f.: x/((1-6*x)*(1-8*x)).
a(n) = (1/2)*(8^n - 6^n).
E.g.f.: exp(7*x)*sinh(x). - G. C. Greubel, Nov 10 2024
MATHEMATICA
CoefficientList[Series[x/((1 - 6 x) (1 - 8 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Aug 07 2013 *)
LinearRecurrence[{14, -48}, {0, 1}, 30] (* Harvey P. Dale, Oct 24 2022 *)
PROG
(Magma) [(8^n-6^n)/2: n in [0..30]]; // Vincenzo Librandi, Aug 07 2013
(SageMath)
A081201=BinaryRecurrenceSequence(14, -48, 0, 1)
[A081201(n) for n in range(41)] # G. C. Greubel, Nov 10 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 11 2003
EXTENSIONS
Name clarified by Pontus von Brömssen, Nov 11 2020
STATUS
approved