a(0)=1; a(1)=2; a(2)=5; a(3)=14; for n>3: a(n) = 8*a(n-1)-20*a(n-2)+16*a(n-3)-a(n-4).
A126566
a(0)=1; a(1)=2; a(2)=5; a(3)=14; for n>3: a(n) = 8*a(n-1)-20*a(n-2)+16*a(n-3)-a(n-4).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =14a(4) =43a(5) =142a(6) =495a(7) =1794a(8) =6681a(9) =25346a(10) =97357a(11) =377038a(12) =1468019a(13) =5735758a(14) =22460935a(15) =88083586a(16) =345754097a(17) =1358000258a(18) =5335796565a(19) =20970349326a(20) =82429113339a(21) =324040664974
External references
- oeis: A126566