VOOZH about

URL: https://oeis.org/A027942

⇱ A027942 - OEIS

login
A027942
a(n) = T(2n+1, n+2), T given by A027935.
1
1, 11, 51, 176, 530, 1490, 4043, 10773, 28445, 74770, 196116, 513876, 1345861, 3524111, 9226935, 24157220, 63245318, 165579398, 433493615, 1134902265, 2971214081, 7778740966, 20365009896, 53316289896, 139583861065, 365435294675, 956722024443, 2504730780248
OFFSET
1,2
FORMULA
a(n) = Fibonacci(2*n+5) - 2*n^2 - 5*n - 5.
G.f.: x*(1+5*x-2*x^2)/((1-x)^3*(1-3*x+x^2)). - Colin Barker, Sep 20 2012
MAPLE
with(combinat): seq(fibonacci(2*n+5) -(2*n^2+5*n+5), n=1..40); # G. C. Greubel, Sep 28 2019
MATHEMATICA
CoefficientList[Series[(1+5x-2x^2)/((1-x)^3*(1-3x+x^2)), {x, 0, 40}], x] (* Vincenzo Librandi, Oct 18 2013 *)
LinearRecurrence[{6, -13, 13, -6, 1}, {1, 11, 51, 176, 530}, 40] (* Harvey P. Dale, Aug 18 2017 *)
PROG
(Magma) [Fibonacci(2*n+5)-2*n^2-5*n-5: n in [1..30]]; // Vincenzo Librandi, Apr 18 2011
(PARI) vector(40, n, fibonacci(2*n+5) -(2*n^2+5*n+5) ) \\ G. C. Greubel, Sep 28 2019
(SageMath) [fibonacci(2*n+5) -(2*n^2+5*n+5) for n in (1..40)] # G. C. Greubel, Sep 28 2019
(GAP) List([1..40], n-> Fibonacci(2*n+5) -(2*n^2+5*n+5) ); # G. C. Greubel, Sep 28 2019
CROSSREFS
Sequence in context: A185505 A051843 A107464 * A168214 A321421 A382537
KEYWORD
nonn,easy
EXTENSIONS
More terms from Vincenzo Librandi, Oct 18 2013
STATUS
approved