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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A284520 a(1) = 1, a(2) = a(3) = a(4) = 2; a(n) = a(a(n-1)-1) + a(n-a(n-3)-1) for n > 4. 1
1, 2, 2, 2, 3, 4, 4, 4, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9, 10, 11, 12, 13, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 17, 18, 19, 19, 19, 19, 20, 22, 25, 28, 28, 26, 24, 23, 25, 29, 30, 31, 30, 30, 30, 31, 31, 31, 31, 32, 32, 32, 32, 32, 32, 32, 32, 33, 34, 35, 35, 35 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Altug Alkan, Table of n, a(n) for n = 1..20000

Altug Alkan, Scatterplot of A284520

EXAMPLE

a(5) = 3 because a(5) = a(a(4)-1) + a(5-a(2)-1) = a(1) + a(2) = 3.

PROG

(PARI) a=vector(1000); a[1]=1; a[2]=a[3]=a[4]=2; for(n=5, #a, a[n]=a[a[n-1]-1]+ a[n-a[n-3]-1]); a

CROSSREFS

Cf. A004001, A005185, A005229, A055748, A070867, A226222, A284511.

Sequence in context: A006949 A194814 A055748 * A090702 A029124 A113512

Adjacent sequences:  A284517 A284518 A284519 * A284521 A284522 A284523

KEYWORD

nonn,look

AUTHOR

Altug Alkan, Mar 28 2017

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 22:04 EST 2018. Contains 299357 sequences. (Running on oeis4.)