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A113442
Third row of A113439.
1
1, 4, 17, 72, 306, 1305, 5577, 23858, 102108, 437080, 1871065, 8009866, 34289712, 146792138, 628407994, 2690174883, 11516466985, 49301256865, 211055514017, 903515089697, 3867890010850, 16558188448465, 70884540117396
OFFSET
0,2
FORMULA
a(n) = A113439(4*n+2).
a(n) = 9*a(n-1) - 28*a(n-2) + 38*a(n-3) - 20*a(n-4) + a(n-5).
G.f.: -(1-5*x+9*x^2-7*x^3+2*x^4)/(-1+9*x-28*x^2+38*x^3-20*x^4+x^5).
MATHEMATICA
CoefficientList[Series[-(1 - 5*x + 9*x^2 - 7*x^3 + 2*x^4)/(-1 + 9*x - 28*x^2 + 38*x^3 - 20*x^4 + x^5), {x, 0, 50}], x] (* G. C. Greubel, Mar 11 2017 *)
PROG
(PARI) x='x+O('x^50); Vec(-(1-5*x+9*x^2-7*x^3+2*x^4)/(-1+9*x-28*x^2+38*x^3-20*x^4+x^5)) \\ G. C. Greubel, Mar 11 2017
CROSSREFS
Cf. A113439.
Sequence in context: A001076 A122451 A257388 * A362908 A085732 A289159
KEYWORD
nonn,easy
AUTHOR
Floor van Lamoen, Nov 04 2005
STATUS
approved