cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A131064 Binomial transform of [1, 1, 5, 5, 5, ...].

Original entry on oeis.org

1, 2, 8, 24, 60, 136, 292, 608, 1244, 2520, 5076, 10192, 20428, 40904, 81860, 163776, 327612, 655288, 1310644, 2621360, 5242796, 10485672, 20971428, 41942944, 83885980, 167772056, 335544212, 671088528, 1342177164, 2684354440
Offset: 0

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Author

Gary W. Adamson, Jun 13 2007

Keywords

Comments

Row sums of triangle A131063. - Emeric Deutsch, Jun 20 2007

Examples

			a(3) = 24 = sum of row 4 terms of A131063: (1 + 11 + 11 + 1).
a(3) = 24 = (1, 3, 3, 1) dot (1, 1, 5, 5).
		

Crossrefs

Programs

  • GAP
    Print(List([0..30],n->5*2^n-4*n-4)); # Muniru A Asiru, Feb 21 2019
    
  • Magma
    I:=[1, 2, 8]; [n le 3 select I[n] else 4*Self(n-1)-5*Self(n-2) + 2*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Jul 05 2012
    
  • Maple
    a := proc (n) options operator, arrow; 5*2^n-4*n-4 end proc: seq(a(n), n = 0 .. 30); # Emeric Deutsch, Jun 20 2007
  • Mathematica
    CoefficientList[Series[(1-2x+5x^2)/((1-2x)(1-x)^2),{x,0,40}],x] (* Vincenzo Librandi, Jul 05 2012 *)
    LinearRecurrence[{4,-5,2},{1,2,8},30] (* Harvey P. Dale, Dec 29 2014 *)
  • Sage
    [5*2^n -4*(n+1) for n in (0..30)] # G. C. Greubel, Mar 12 2020

Formula

From Emeric Deutsch, Jun 20 2007: (Start)
a(n) = 5*2^n - 4*(n + 1).
G.f.: (1-2*x+5*x^2)/((1-2*x)*(1-x)^2). (End)
a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3). - Vincenzo Librandi, Jul 05 2012
E.g.f.: 5*exp(2*x) - 4*(1+x)*exp(x). - G. C. Greubel, Mar 12 2020

Extensions

Corrected and extended by Emeric Deutsch, Jun 20 2007