login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A087775 a[1] = 1, a[2] = 2, a[3] = 2; a[n] = 3*a[abs[a[n-2]]] - 3*a[n-abs[a[n-2]]] + a[n-3]. 2

%I

%S 1,2,2,1,2,-1,1,2,-4,1,2,-7,1,2,-10,1,2,-13,1,2,-16,1,2,-19,1,2,-22,1,

%T 2,-25,1,2,-28,1,2,-31,1,2,-34,1,2,-37,1,2,-40,1,2,-43,1,2,-46,1,2,

%U -49,1,2,-52,1,2,-55,1,2,-58,1,2,-61,1,2,-64,1,2,-67,1,2,-70,1,2,-73,1,2,-76,1,2,-79,1,2,-82,1,2,-85,1,2,-88,1,2,-91,1,2

%N a[1] = 1, a[2] = 2, a[3] = 2; a[n] = 3*a[abs[a[n-2]]] - 3*a[n-abs[a[n-2]]] + a[n-3].

%C A recursive sequence based on A087774 and the Mallows A005229 sequence. A tick-tock sequence where the form is: 1,2,a(n-3)-3

%t hg[n_Integer?Positive] := hg[n] =3*hg[Abs[hg[n-2]]] -3*hg[n-Abs[hg[n-2]]]+hg[n-3] hg[1] =1 hg[2] =2 hg[3]=2 digits=200 a=Table[hg[n], {n, 1, digits}]

%Y Cf. A005229.

%K sign

%O 1,2

%A _Roger L. Bagula_, Oct 04 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 11 19:26 EDT 2022. Contains 356066 sequences. (Running on oeis4.)