A118415 a(n) = (4*n - 3) * 2^(n - 1).

1, 10, 36, 104, 272, 672, 1600, 3712, 8448, 18944, 41984, 92160, 200704, 434176, 933888, 1998848, 4259840, 9043968, 19136512, 40370176, 84934656, 178257920, 373293056, 780140544, 1627389952, 3388997632, 7046430720, 14629732352, 30333206528, 62813896704

Offset

1,2

Comments

Central terms of the triangle in A118413.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

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

Formula

a(n) = A016813(n-1)*A000079(n-1).

O.g.f.: x*(1+6*x)/(-1+2*x)^2 . - R. J. Mathar, Feb 26 2008

Mathematica

CoefficientList[Series[(1 + 6 x)/(-1 + 2 x)^2, {x, 0, 40}], x] (* Vincenzo Librandi, May 21 2014 *)
LinearRecurrence[{4, -4}, {1, 10}, 30] (* Harvey P. Dale, Sep 16 2022 *)

Prog

(Magma)[(4*n-3)*2^(n-1): n in [1..40]]; // Vincenzo Librandi, Dec 26 2010

Crossrefs

Cf. A058962.

Sequence in context: A118629 A050509 A211057 * A051959 A117327 A153371

Adjacent sequences: A118412 A118413 A118414 * A118416 A118417 A118418

Keyword

nonn,easy

Author

Reinhard Zumkeller, Apr 27 2006

Extensions

More terms from R. J. Mathar, Feb 26 2008

Status

approved