0,2

G.f.: (1-6x)/(1-10x+20x^2); a(n)=(5-sqrt(5))(5+sqrt(5))^n/10 + (5+sqrt(5))(5-sqrt(5))^n/10; a(n)=2^n*A093129(n).

Cf. A000045.

Sequence in context: A013197 A089498 A046729 this_sequence A092055 A001715 A020028

Adjacent sequences: A093120 A093121 A093122 this_sequence A093124 A093125 A093126

easy,nonn

Paul Barry (pbarry(AT)wit.ie), Mar 23 2004