0,2

a(n)=2*a(n-1)+a(n-1)+7; a(0)=1, a(1)=9.

a(n)=[ {(8+(9/2)*sqrt(2))(1+sqrt(2))^n -(8-(9/2)*sqrt(2))(1-sqrt(2))^n}/ 2*sqrt(2) ]-7/2.

Cf. A001333, A000129, A048694, A048695.

Sequence in context: A154560 A052153 A048468 this_sequence A055849 A084813 A056409

Adjacent sequences: A048768 A048769 A048770 this_sequence A048772 A048773 A048774

easy,nice,nonn

Barry E. Williams