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A213044
Convolution of Fibonacci numbers and positive integers repeated three times (A000045 and A008620).
1
1, 1, 2, 5, 7, 12, 22, 34, 56, 94, 150, 244, 399, 643, 1042, 1691, 2733, 4424, 7164, 11588, 18752, 30348, 49100, 79448, 128557, 208005, 336562, 544577, 881139, 1425716, 2306866, 3732582, 6039448, 9772042, 15811490, 25583532, 41395035
OFFSET
0,3
FORMULA
a(n) = a(n-1)+2*a(n-2)-2*a(n-3)-2*a(n-4)-a(n-5)+a(n-6)+a(n-7).
G.f.: 1/((1 - x - x^2)*(1 - x^3)^2).
MATHEMATICA
f[x_] := (1 - x^3)^2; g[x] := 1 - x - x^2;
s = Normal[Series[1/(f[x] g[x]), {x, 0, 60}]]
c = CoefficientList[s, x] (* A213044 *)
CROSSREFS
Cf. A213500.
Sequence in context: A359064 A333068 A029938 * A269769 A230428 A071013
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 10 2012
STATUS
approved