A060195 a(n) = 8^(n-1)*(2^n - 1).

1, 24, 448, 7680, 126976, 2064384, 33292288, 534773760, 8573157376, 137304735744, 2197949513728, 35175782154240, 562881233944576, 9006649498927104, 144110790029344768, 2305807824841605120, 36893206672442392576, 590293558558891966464, 9444714951340780945408

Offset: 1

Author

Manish Kumar Gupta (M.Gupta(AT)math.canterbury.ac.nz), Mar 21 2001

Keywords

• nonn
• easy

Links

• Harry J. Smith, Table of n, a(n) for n = 1..100
• Index entries for linear recurrences with constant coefficients, signature (24,-128).

Crossrefs

Cf. A000225, A001018.

Programs

Magma

[8^(n-1)*(2^n-1): n in [1..40]]; // G. C. Greubel, Aug 01 2024

Mathematica

Table[8^(n-1) (2^n-1),{n,20}] (* or *) LinearRecurrence[{24,-128},{1,24},20] (* Harvey P. Dale, Oct 20 2014 *)

PARI

{ a(n) = 8^(n - 1)*(2^n - 1) } \\ Harry J. Smith, Jul 02 2009

SageMath

[8^(n-1)*(2^n-1) for n in range(1,41)] # G. C. Greubel, Aug 01 2024

Formula

a(1)=1, a(2)=24, a(n) = 24*a(n-1) - 128*a(n-2). - Harvey P. Dale, Oct 20 2014

From G. C. Greubel, Aug 01 2024: (Start)

a(n) = A000225(n)*A001018(n-1).

G.f.: x/((1 - 8*x)*(1 - 16*x)).

E.g.f.: (1/4)*exp(12*x)*sinh(4*x). (End)

Extensions

More terms from Jason Earls and Larry Reeves (larryr(AT)acm.org), Mar 21 2001