A156550 a(n) = 5*(-1)^n*A078008(n).

5, 0, 10, -10, 30, -50, 110, -210, 430, -850, 1710, -3410, 6830, -13650, 27310, -54610, 109230, -218450, 436910, -873810, 1747630, -3495250, 6990510, -13981010, 27962030, -55924050, 111848110, -223696210, 447392430, -894784850, 1789569710, -3579139410

Offset: 0

Author

Paul Curtz, Feb 09 2009

Keywords

• sign
• easy
• less

Links

• Index entries for linear recurrences with constant coefficients, signature (-1,2).

Crossrefs

Cf. A001045, A078008, A140966.

Programs

Mathematica

LinearRecurrence[{-1, 2}, {5, 0}, 32] (* Robert P. P. McKone, Jan 31 2021 *)

Formula

a(n) = A140966(n)+A140966(n+2).

a(n) = 3*A140966(n)-A140966(n+1).

a(n+1) = 10*(-1)^n*A001045(n).

G.f.: 5*(1+x)/(1+x-2*x^2). - R. J. Mathar, Feb 23 2009

a(n) = (5*(2+(-2)^n))/3. - Colin Barker, Jun 10 2012

a(n) = -a(n-1) + 2*a(n-2) for n > 1. - Klaus Purath, Jan 30 2021

E.g.f.: 5*exp(-2*x)*(1 + 2*exp(3*x))/3. - Stefano Spezia, Jan 30 2021

Extensions

Edited and extended by R. J. Mathar Feb 23 2009