OFFSET
1,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7).
G.f.: x*(1 + 3 x + 2*x^2)/(1 - x)^7.
MATHEMATICA
(See A213561.)
LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {1, 10, 51, 182, 518, 1260, 2730}, 40] (* Harvey P. Dale, Aug 10 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 18 2012
STATUS
approved