login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A180234 Demi-tribonacci numbers (rounding down): a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 ) 1
0, 0, 2, 1, 1, 2, 2, 2, 3, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 30, 37, 45, 56, 69, 85, 105, 129, 159, 196, 242, 298, 368, 454, 560, 691, 852, 1051, 1297, 1600, 1974, 2435, 3004, 3706, 4572, 5641, 6959, 8586, 10593, 13069, 16124, 19893, 24543, 30280, 37358, 46090 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..55.

FORMULA

a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 )

For n>9, a(n)=A180235(n-4)+1

a(n)/a(n-1) tends to 1.233751928528... which is a root of 2*x^3 - x^2 - x - 1 = 0

CROSSREFS

Cf. A000213, A180235

Sequence in context: A161105 A048165 A161040 * A131059 A133098 A145788

Adjacent sequences:  A180231 A180232 A180233 * A180235 A180236 A180237

KEYWORD

easy,nonn

AUTHOR

Carl R. White, Aug 18 2010

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 26 05:07 EDT 2021. Contains 347664 sequences. (Running on oeis4.)