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 A175109 a(n) = ((2*n+1)^3+(-1)^n)/2. 2
 1, 13, 63, 171, 365, 665, 1099, 1687, 2457, 3429, 4631, 6083, 7813, 9841, 12195, 14895, 17969, 21437, 25327, 29659, 34461, 39753, 45563, 51911, 58825, 66325, 74439, 83187, 92597, 102689, 113491, 125023, 137313, 150381, 164255, 178955 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Partial sums of A110907. Convolution of the finite sequence (1,10,26,10,1) with A002623. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (3,-2,-2,3,-1). FORMULA a(n) = 3*a(n-1) -2*a(n-2) -2*a(n-3) +3*a(n-4) -a(n-5). G.f.: (x^2+4*x+1)*(x^2+6*x+1)/((1+x)*(x-1)^4). MAPLE A175109:=n->((2*n+1)^3+(-1)^n)/2: seq(A175109(n), n=0..50); # Wesley Ivan Hurt, Apr 18 2017 MATHEMATICA CoefficientList[Series[(x^2 + 4*x + 1)*(x^2 + 6*x + 1)/((1 + x)*(x - 1)^4), {x, 0, 40}], x] (* Vincenzo Librandi, Dec 19 2012 *) PROG (MAGMA) I:=[1, 13, 63, 171, 365]; [n le 5 select I[n] else 3*Self(n-1) - 2*Self(n-2) - 2*Self(n-3) + 3*Self(n-4) - Self(n-5): n in [1..40]]; // Vincenzo Librandi, Dec 19 2012 CROSSREFS Cf. A002623, A110907. Sequence in context: A213843 A031074 A285482 * A265038 A051878 A092653 Adjacent sequences:  A175106 A175107 A175108 * A175110 A175111 A175112 KEYWORD easy,nonn AUTHOR R. J. Mathar, Feb 13 2010 STATUS approved

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Last modified February 16 14:47 EST 2019. Contains 320163 sequences. (Running on oeis4.)