A084568 a(0)=1, a(1)=5, a(n+2)=4a(n), n>0.

1, 5, 8, 20, 32, 80, 128, 320, 512, 1280, 2048, 5120, 8192, 20480, 32768, 81920, 131072, 327680, 524288, 1310720, 2097152, 5242880, 8388608, 20971520, 33554432, 83886080, 134217728, 335544320, 536870912, 1342177280, 2147483648

Offset: 0

Author

Paul Barry, May 30 2003

Keywords

• nonn
• easy

Comments

Binomial transform is A080926 (without leading zero).

Links

• Index entries for linear recurrences with constant coefficients, signature (0,4)

Crossrefs

Cf. A080926, A104721.

Programs

Mathematica

Join[{1},LinearRecurrence[{0,4},{5,8},30]] (* Harvey P. Dale, Sep 12 2013 *)

Formula

G.f.: (1+5*x+4*x^2)/((1+2*x)*(1-2*x)).

E.g.f.: (9*exp(2*x)-exp(-2*x))/4-exp(0).

a(n) = (9*2^n-(-2)^n)/4-0^n.