A048468 a(n) = T(7,n), array T given by A047858.

1, 9, 26, 62, 138, 298, 634, 1338, 2810, 5882, 12282, 25594, 53242, 110586, 229370, 475130, 983034, 2031610, 4194298, 8650746, 17825786, 36700154, 75497466, 155189242, 318767098, 654311418, 1342177274, 2751463418, 5637144570, 11542724602, 23622320122

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• easy

Comments

n-th difference of a(n), a(n-1), ..., a(0) is (8, 9, 10, ...).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..3000
• Index entries for linear recurrences with constant coefficients, signature (5, -8, 4).

Programs

Magma

[2^(n-1)*(n+14)-6: n in [0..30]]; // Vincenzo Librandi, Sep 28 2011

Mathematica

LinearRecurrence[{5,-8,4},{1,9,26},30] (* Harvey P. Dale, Apr 19 2012 *)

PARI

Vec((1+4*x-11*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Feb 18 2016

Formula

a(n) = 2^(n-1)*(n+14)-6. a(0)=1, a(1)=9, a(2)=26, a(n) = 5*a(n-1)-8*a(n-2)+4*a(n-3). - Vincenzo Librandi, Sep 28 2011

a(n) = 2^(n-1)*(n+14)-6. G.f.: (1+4*x-11*x^2) / ((1-x)*(1-2*x)^2). - Colin Barker, Feb 18 2016