0,2

a(n) = 2 A000045(n+2) + A000045(n) - 1 GF: (1+2*x-2*x^2)/(x^3-2*x+1); a(0)=1,a(1)=4,a(2)=6,a(n)=2 a(n-1) - a(n-3) - Ron Knott (enquiry(AT)ronknott.com), Aug 25 2006

Cf. A122195.

Sequence in context: A008369 A060577 A058579 this_sequence A047811 A091280 A066155

Adjacent sequences: A022315 A022316 A022317 this_sequence A022319 A022320 A022321

nonn

njas