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

0,2

Links

Table of n, a(n) for n=0..26.

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

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

Mathematica

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

Crossrefs

Cf. A010892, A077947, A133405, A122392.

Sequence in context: A148359 A287582 A122392 * A378339 A047086 A071731

Adjacent sequences: A139779 A139780 A139781 * A139783 A139784 A139785

Keyword

nonn,easy

Author

Paul Curtz, May 16 2008

Extensions

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

Status

approved