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.

A257273 a(n) = 2^(n-1)*(2^n+3).

Original entry on oeis.org

2, 5, 14, 44, 152, 560, 2144, 8384, 33152, 131840, 525824, 2100224, 8394752, 33566720, 134242304, 536920064, 2147581952, 8590131200, 34360131584, 137439739904, 549757386752, 2199026401280, 8796099313664, 35184384671744, 140737513521152, 562950003752960, 2251799914348544, 9007199456067584
Offset: 0

Views

Author

M. F. Hasler, Apr 27 2015

Keywords

Comments

a(n) is in A125246 <=> n is in A057732 <=> A062709(n) is in A057733.
These are also the row sum of the triangle A146769: For n>=1, a(n-1) is the sum of row n of A146769.

Crossrefs

Programs

  • Magma
    [2^(n-1)*(2^n+3): n in [0..35]]; // Vincenzo Librandi, Apr 27 2015
    
  • Mathematica
    Table[2^(n - 1) (2^n + 3), {n, 0, 30}] (* Bruno Berselli, Apr 27 2015 *)
    CoefficientList[Series[(2 - 7 x)/((1 - 4 x) (1 - 2 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Apr 27 2015 *)
    LinearRecurrence[{6,-8},{2,5},30] (* Harvey P. Dale, Dec 21 2024 *)
  • PARI
    a(n)=2^(n-1)*(2^n+3)
    
  • PARI
    Vec((2-7*x)/((1-4*x)*(1-2*x)) + O(x^100)) \\ Colin Barker, Apr 27 2015

Formula

G.f.: (2-7*x)/((1-4*x)*(1-2*x)). - Vincenzo Librandi, Apr 27 2015
a(n) = 6*a(n-1)-8*a(n-2). - Colin Barker, Apr 27 2015