A137531 a(n) = 3*a(n-1) - 2*a(n-2) + a(n-3).
1, 4, 10, 23, 53, 123, 286, 665, 1546, 3594, 8355, 19423, 45153, 104968, 244021, 567280, 1318766, 3065759, 7127025, 16568323, 38516678, 89540413, 208156206, 483904470, 1124941411, 2615171499, 6079536145, 14133206848, 32855719753, 76380281708, 177562612466
Offset: 0
Links
- G. C. Greubel, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (3,-2,1).
Programs
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Mathematica
LinearRecurrence[{3, -2, 1}, {1, 4, 10}, 100] (* G. C. Greubel, Feb 17 2017 *) -
PARI
a=[1,4,10];for(i=1,99,a=concat(a,3*a[#a]-2*a[#a-1]+a[#a-2]));a \\ Charles R Greathouse IV, Jun 01 2011
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PARI
Vec((1 + x) / (1 - 3*x + 2*x^2 - x^3) + O(x^40)) \\ Colin Barker, Feb 17 2017
Formula
G.f.: (1 + x) / (1 - 3*x + 2*x^2 - x^3). - Colin Barker, Feb 17 2017
Extensions
More terms from Vladimir Joseph Stephan Orlovsky, Jan 20 2009