A048479 a(n) = T(7,n), array T given by A048472.
1, 9, 33, 97, 257, 641, 1537, 3585, 8193, 18433, 40961, 90113, 196609, 425985, 917505, 1966081, 4194305, 8912897, 18874369, 39845889, 83886081, 176160769, 369098753, 771751937, 1610612737, 3355443201, 6979321857, 14495514625, 30064771073, 62277025793
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (5,-8,4).
Crossrefs
Cf. A048472.
Programs
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Magma
[8*n * 2^(n-1) + 1: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011
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Mathematica
Table[8 n*2^(n - 1) + 1, {n, 0, 29}] (* or *) CoefficientList[Series[(1 + 4 x - 4 x^2)/((1 - x) (1 - 2 x)^2), {x, 0, 29}], x] (* Michael De Vlieger, Sep 22 2017 *) -
PARI
Vec((1+4*x-4*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Feb 18 2016
Formula
a(n) = 8*n * 2^(n-1) + 1.
a(n) = 5*a(n-1)-8*a(n-2)+4*a(n-3) for n>2. G.f.: (1+4*x-4*x^2) / ((1-x)*(1-2*x)^2). - Colin Barker, Feb 18 2016
a(n) = Sum_{k=0..n+2} Sum_{i=0..n+2} C(n+1,i) - C(k,i). - Wesley Ivan Hurt, Sep 21 2017
Comments