OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Silvana Ramaj, New Results on Cyclic Compositions and Multicompositions, Master's Thesis, Georgia Southern Univ., 2021. See p. 67.
Index entries for linear recurrences with constant coefficients, signature (14,-49).
FORMULA
a(n) = 14*a(n-1) - 49*a(n-2) for n>1, a(0)=1, a(1)=13.
a(n) = (6*n+7)*7^(n-1).
a(n) = Sum_{k=0..n} (k+1)*6^k*binomial(n, k).
G.f.: (1-x)/(1-7*x)^2.
MATHEMATICA
CoefficientList[Series[(1 - x)/(1 - 7 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
LinearRecurrence[{14, -49}, {1, 13}, 20] (* Harvey P. Dale, Jan 24 2014 *)
PROG
(Magma) [(6*n+7)*7^(n-1): n in [0..25]]; // Vincenzo Librandi, Aug 06 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 04 2003
STATUS
approved