1,1

a(n) = ( 10*n + 7 + (-1)^n ) / 4.

G.f.: (2+2x+x^2)/((1+x)(1-x)^2); [From Paul Barry (pbarry(AT)wit.ie), Sep 11 2008]

Adjacent sequences: A047208 A047209 A047210 this_sequence A047212 A047213 A047214

Sequence in context: A022840 A064995 A067839 this_sequence A087733 A065027 A165994

nonn

N. J. A. Sloane (njas(AT)research.att.com).