A048500 a(n) = 2^(n-1)*(7*n-12) + 7.

1, 2, 11, 43, 135, 375, 967, 2375, 5639, 13063, 29703, 66567, 147463, 323591, 704519, 1523719, 3276807, 7012359, 14942215, 31719431, 67108871, 141557767, 297795591, 624951303, 1308622855, 2734686215, 5704253447, 11878268935, 24696061959, 51271172103

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5,-8,4).

Formula

a(n) = T(6,n), array T given by A048494.

a(n) = 5*a(n-1) - 8*a(n-2) + 4*a(n-3), a(0)=1, a(1)=2, a(2)=11. - Harvey P. Dale and Vincenzo Librandi, Sep 23 2011

G.f.: (1-3*x+9*x^2)/((1-x)*(1-2*x)^2). - Colin Barker, Aug 24 2016

E.g.f.: exp(x)*(7 + exp(x)*(7*x - 6)). - Elmo R. Oliveira, Oct 27 2025

Prog

(Magma) [2^(n-1)*(7*n-12)+7: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011
(PARI) Vec((1-3*x+9*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Aug 24 2016

Crossrefs

Cf. A048494.

Sequence in context: A379617 A379515 A141190 * A387868 A197189 A050620

Adjacent sequences: A048497 A048498 A048499 * A048501 A048502 A048503

Keyword

nonn,easy

Author

Clark Kimberling

Extensions

Formula from Ralf Stephan, Jan 15 2004

Status

approved