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A167387
a(n) = (-1)^(n+1) * n*(n-1)*(n-4)*(n+1)/12.
2
1, -2, 0, 10, -35, 84, -168, 300, -495, 770, -1144, 1638, -2275, 3080, -4080, 5304, -6783, 8550, -10640, 13090, -15939, 19228, -23000, 27300, -32175, 37674, -43848, 50750, -58435, 66960, -76384, 86768, -98175, 110670, -124320, 139194, -155363, 172900
OFFSET
2,2
COMMENTS
The coefficient of [x^4] of the Polynomial B_{2n}(x) defined in A137276.
Essentially the same as A052472.
FORMULA
a(n) = -5*a(n-1) -10*a(n-2) -10*a(n-3) -5*a(n-4) -a(n-5).
G.f.: x^2*(1+3*x)/(1+x)^5.
E.g.f.: x^2*(6 + 2*x - x^2)*exp(-x)/12. - G. C. Greubel, May 19 2019
MATHEMATICA
Table[(-1)^(n+1)*(n+1)*n*(n-1)*(n-4)/12, {n, 2, 40}] (* G. C. Greubel, Jun 12 2016 *)
LinearRecurrence[{-5, -10, -10, -5, -1}, {1, -2, 0, 10, -35}, 40] (* Vincenzo Librandi, Jun 13 2016 *)
PROG
(Magma) [(-1)^(n+1)*n*(n-1)*(n-4)*(n+1)/12: n in [2..40]]; // Vincenzo Librandi, Jun 13 2016
(PARI) vector(40, n, n++; (-1)^(n+1)*(n-4)*binomial(n+1, 3)/2) \\ G. C. Greubel, May 19 2019
(Sage) [(-1)^(n+1)*(n-4)*binomial(n+1, 3)/2 for n in (2..40)] # G. C. Greubel, May 19 2019
(GAP) List([2..40], n-> (-1)^(n+1)*(n-4)*Binomial(n+1, 3)/2) # G. C. Greubel, May 19 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Jamel Ghanouchi, Nov 02 2009
STATUS
approved