A027016 T(2n+1,n+1), T given by A027011.

1, 5, 28, 98, 291, 806, 2164, 5729, 15072, 39542, 103615, 271370, 710568, 1860413, 4870756, 12751946, 33385179, 87403694, 228826012, 599074457, 1568397480, 4106118110, 10749956983, 28143752978, 73681302096, 192900153461, 505019158444, 1322157322034

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• Nathaniel Johnston, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (5,-8,5,-1).

Programs

Mathematica

LinearRecurrence[{5,-8,5,-1},{1,5,28,98,291},30] (* Harvey P. Dale, Aug 08 2019 *)

PARI

Vec((1+11*x^2-7*x^3+x^4)/((1-x)^2*(1-3*x+x^2)) + O(x^40)) \\ Colin Barker, Feb 17 2016

Formula

For n>0, a(n) = Fibonacci(2n+6) - Fibonacci(2n+2) - 6n - 7.

From Colin Barker, Feb 17 2016: (Start)

a(n) = 5*a(n-1)-8*a(n-2)+5*a(n-3)-a(n-4) for n>4.

G.f.: (1+11*x^2-7*x^3+x^4) / ((1-x)^2*(1-3*x+x^2)).

(End)

Extensions

a(22) - a(25) from Vincenzo Librandi, Apr 18 2011