0,2

A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

a(n)=(3^n/4)*[(3^(n+1))+(-1)^n].

a(n)=6a(n-1)+27a(n-2); a(0)=1.

Cf. A015518.

Sequence in context: A027950 A053700 A123615 this_sequence A039937 A134112 A071588

Adjacent sequences: A053532 A053533 A053534 this_sequence A053536 A053537 A053538

easy,nonn

Barry E. Williams, Jan 15 2000