OFFSET
1,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).
FORMULA
a(n) = (16/35)*n^7 + (1/2)*n^6 + (1/15)*n^3 - (1/42)*n.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
G.f.: x*(1 + 83*x + 666*x^2 + 1106*x^3 + 421*x^4 + 27*x^5)/(1 - x)^8
MATHEMATICA
(See A213558.)
LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {1, 91, 1366, 9542, 43535, 151313, 435324, 1089804}, 40] (* Harvey P. Dale, Oct 09 2016 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 17 2012
STATUS
approved