0,3

a(n)=2*4^n/3-5/12-n*3^(n-1)/2-3^n/4

O.g.f.: x*(1-6*x+10*x^2)/[(-1+x)(-1+4*x)(-1+3*x)^2]. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 02 2008

Sequence in context: A116415 A026861 A026888 this_sequence A129158 A129164 A123347

Adjacent sequences: A083583 A083584 A083585 this_sequence A083587 A083588 A083589

easy,nonn

Paul Barry (pbarry(AT)wit.ie), May 01 2003