A139782 Binomial transform of A077947.

1, 2, 5, 15, 46, 139, 417, 1250, 3749, 11247, 33742, 101227, 303681, 911042, 2733125, 8199375, 24598126, 73794379, 221383137, 664149410, 1992448229, 5977344687, 17932034062, 53796102187, 161388306561, 484164919682, 1452494759045

Offset: 0

Author

Paul Curtz, May 16 2008

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (4,-4,3).

Crossrefs

Cf. A010892, A077947, A133405, A122392.

Programs

Mathematica

LinearRecurrence[{3,0,-1,3},{1,2,5,15},30] (* Harvey P. Dale, Jan 12 2019 *)

Formula

a(n) = 3*a(n-1)-a(n-3)+3*a(n-4).

O.g.f.: -(1-x)^2/((3*x-1)*(x^2-x+1)). a(n) = (4*3^n+3*A010892(n)-A010892(n-1))/7. - R. J. Mathar, May 18 2008

Extensions

More terms from R. J. Mathar, May 18 2008