A152032 - OEIS

A152032

a(n) = 3/8 + (3/8)*(-1)^n + ((n+1)/4)*(-1)^(n+1) + ((n+2)*(n+1)/4)*(-1)^(n+2).

1, -1, 3, -4, 7, -9, 13, -16, 21, -25, 31, -36, 43, -49, 57, -64, 73, -81, 91, -100, 111, -121, 133, -144, 157, -169, 183, -196, 211, -225, 241, -256, 273, -289, 307, -324, 343, -361, 381, -400, 421, -441, 463, -484, 507, -529, 553, -576, 601, -625, 651

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..50.

Index entries for linear recurrences with constant coefficients, signature (-2,0,2,1)

FORMULA

O.g.f.: (1+z+z^2)/((1-z)*(1+z)^3).

a(n+4) = -2*a(n+3) + 2*a(n+1) + a(n).

MATHEMATICA

LinearRecurrence[{-2, 0, 2, 1}, {1, -1, 3, -4}, 60] (* Harvey P. Dale, Sep 23 2019 *)

CROSSREFS