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A290914
a(n) = (1/7)*A290913(n).
3
0, 1, 4, 17, 76, 336, 1484, 6559, 28988, 128111, 566184, 2502240, 11058600, 48873265, 215994436, 954583169, 4218761572, 18644733936, 82400035556, 364165339279, 1609421566844, 7112807014943, 31434910948176, 138925971735744, 613980604384080, 2713475226049825
OFFSET
0,3
FORMULA
G.f.: x/(1 - 4 x - x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) + a(n-2) + 4*a(n-3) - a(n-4).
a(n) = (1/7)*A290913(n) for n >= 0.
MATHEMATICA
z = 60; s = x/(1 - x)^2; p = 1 - 7 s^2;
Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290913 *)
u/7 (* A290914 *)
LinearRecurrence[{4, 1, 4, -1}, {0, 1, 4, 17}, 30] (* Harvey P. Dale, May 05 2019 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Aug 18 2017
STATUS
approved