A333588 a(n) = floor(-(3/2)*a(n-1)), a(1)=-2.

-2, 3, -5, 7, -11, 16, -24, 36, -54, 81, -122, 183, -275, 412, -618, 927, -1391, 2086, -3129, 4693, -7040, 10560, -15840, 23760, -35640, 53460, -80190, 120285, -180428, 270642, -405963, 608944, -913416, 1370124, -2055186, 3082779, -4624169, 6936253, -10404380, 15606570, -23409855, 35114782

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Example

floor(-(3/2) *  -2) =   3;
floor(-(3/2) *   3) =  -5;
floor(-(3/2) *  -5) =   7;
floor(-(3/2) *   7) = -11;
floor(-(3/2) * -11) =  16;
floor(-(3/2) *  16) = -24.

Mathematica

Nest[Append[#1, Floor[-3 #1[[-1]]/2]] & @@ {#, Mod[Length@ #, 2]} &, {-2}, 44] (* Michael De Vlieger, Mar 27 2020 *)
NestList[Floor[-3/2 #] &, -2, 50] (* Alonso del Arte, Mar 29 2020 *)

Prog

(Ruby) values = [-2]; 100.times { values << (values.last * -3/2) }; p values

Crossrefs

Cf. A061419.

Sequence in context: A083198 A333589 A112088 * A117792 A154888 A271485

Adjacent sequences: A333585 A333586 A333587 * A333589 A333590 A333591

Keyword

sign

Author

Simon Strandgaard, Mar 27 2020

Status

approved