A048487 a(n) = T(4,n), array T given by A048483.

1, 6, 16, 36, 76, 156, 316, 636, 1276, 2556, 5116, 10236, 20476, 40956, 81916, 163836, 327676, 655356, 1310716, 2621436, 5242876, 10485756, 20971516, 41943036, 83886076, 167772156, 335544316, 671088636, 1342177276, 2684354556

Offset

0,2

Comments

Row sums of triangle A131113. - Gary W. Adamson, Jun 15 2007

a(n) = sum of (n+1)-th row terms of triangle A134636. This sequence is the binomial transform of 1, 5, 5, (5 continued). - Gary W. Adamson, Nov 04 2007

Row sums of triangle A135856. - Gary W. Adamson, Dec 01 2007

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,-2).

Formula

a(n) = 5*2^n - 4. - Henry Bottomley, May 29 2001

a(n) = 2*a(n-1) + 4 for n > 0 with a(0) = 1. - Paul Barry, Aug 25 2004

From Colin Barker, Sep 13 2012: (Start)

a(n) = 3*a(n-1) - 2*a(n-2) for n >= 2.

G.f.: (1 + 3*x)/((1 - x)*(1 - 2*x)). (End)

a(n) = A123208(2*n). - Philippe Deléham, Apr 15 2013

Mathematica

a=1; lst={a}; k=5; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 15 2008 *)
a=6; lst={1, a}; k=10; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 17 2008 *)

Prog

(Magma)[5*2^n-4: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011

Crossrefs

Cf. A010716 (n-th difference of a(n), a(n-1), ..., a(0)).

Diagonal of A062001.

A column of A119726.

Cf. A048483, A131113, A134636, A135856.

Sequence in context: A247619 A120586 A171373 * A124699 A237601 A064602

Adjacent sequences: A048484 A048485 A048486 * A048488 A048489 A048490

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved