A189743 a(1)=4, a(2)=4, a(n) = 4*a(n-1) + 4*a(n-2)

4, 4, 32, 144, 704, 3392, 16384, 79104, 381952, 1844224, 8904704, 42995712, 207601664, 1002389504, 4839964672, 23369416704, 112837525504, 544827768832, 2630661177344, 12701955784704, 61330467848192, 296129694531584, 1429840649519104, 6903881376202752

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..100

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

Formula

G.f.: 4*x*(1-3*x)/(1-4*x-4*x^2). - Bruno Berselli, May 24 2011

Mathematica

LinearRecurrence[{4, 4}, {4, 4}, 40]

Prog

(Maxima) a[1]:4$ a[2]:4$ a[n]:=4*a[n-1]+4*a[n-2]$ makelist(a[n], n, 1, 24); /* Bruno Berselli, May 24 2011 */

Crossrefs

Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734, A189735, A189736, A189737, A189738, A189739, A189741, A189742, A189744, A189745, A189746, A189747, A189748, A189749.

Sequence in context: A271003 A217310 A298681 * A089542 A222285 A222504

Adjacent sequences: A189740 A189741 A189742 * A189744 A189745 A189746

Keyword

nonn,easy

Author

Harvey P. Dale, Apr 26 2011

Status

approved