login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A141435 a(1) = 1, a(2) = 2; a(n) = a(n-a(1)) + a(n-a(2)) + a(n-a(3)) + a(n-a(4)) + ... 1
1, 2, 3, 6, 11, 20, 38, 71, 132, 247, 461, 861, 1609, 3005, 5613, 10485, 19584, 36581, 68330, 127632, 238404, 445314, 831798, 1553712, 2902170, 5420945, 10125754, 18913838, 35329048, 65990929, 123264078, 230244265, 430071949, 803328933 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Thus we get a self-reference sequence that grows exponentially. a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-6) + a(n-11) + a(n-20) + ...

A fibonacci-like sequence, even closer to the tribonacci numbers.

Lim n-> oo log (a(n))/n converges.

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

a(6) = 20 because 20 = a(5) + a(4) + a(3) = 11 + 6 + 3

a(8) = 71 because 71 = a(7) + a(6) + a(5) + a(2) = 38 + 20 + 11 + 2

MAPLE

A141435 := proc(n) option remember; local a, i; if n <= 3 then RETURN(n); else a :=0 ; for i from 1 to n-1 do if n-procname(i) < 1 then RETURN(a); else a := a+procname(n-procname(i)) ; fi; od; RETURN(a); fi; end: for n from 1 to 80 do printf("%d, ", A141435(n)) ; od: # R. J. Mathar, Nov 03 2008

CROSSREFS

Cf. A058265, A008937, A001590, A000213, A000073, A096436, A102575, A111129.

Sequence in context: A115792 A054177 A186546 * A096080 A143658 A005230

Adjacent sequences:  A141432 A141433 A141434 * A141436 A141437 A141438

KEYWORD

easy,nonn

AUTHOR

Raes Tom (tommy1729(AT)hotmail.com), Aug 06 2008

EXTENSIONS

More terms from R. J. Mathar, Nov 03 2008

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 19 12:48 EST 2018. Contains 299333 sequences. (Running on oeis4.)