0,3

Closed walks of length n at a vertex of the Johnson graph J(5,2). 6^n=A091054(n)+6*A091055(n)+3*4*A091056(n).

a(n)=6^n/10+(-2)^n/2+2/5

Sequence in context: A012758 A003496 A009582 this_sequence A012774 A027744 A077531

Adjacent sequences: A091051 A091052 A091053 this_sequence A091055 A091056 A091057

easy,nonn

Paul Barry (pbarry(AT)wit.ie), Dec 17 2003