A134987 Third extended Jacobsthal recurrence: a(n)=4a(n-1)-6(n-2)+4a(n-3)-a(n-4)+2a(n-5).

0, 0, 0, 0, 1, 4, 10, 20, 35, 58, 100, 192, 405, 880, 1874, 3844, 7631, 14886, 29020, 57192, 114249, 230300, 465226, 936948, 1877771, 3748498, 7470532, 14895728, 29749837, 59514152, 119166962, 238627620, 477606935, 955315390, 1909991772, 3818208792

Offset: 0

Author

Paul Curtz, Feb 05 2008

Keywords

• nonn
• easy

Comments

See A134658. Sequence is identical to half its fourth differences from second term.

Links

• Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1, 2).

Programs

Mathematica

LinearRecurrence[{4,-6,4,-1,2},{0,0,0,0,1},60] (* Harvey P. Dale, Jul 12 2011 *)

Formula

O.g.f.: -1/[9(2x-1)]+(-4x^3-2x^2-1)/[9(x^4+2x^2-2x+1)]. - R. J. Mathar, Feb 06 2008

Extensions

More terms from Harvey P. Dale, Jul 12 2011