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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107355 Nonprimes of the form r(r(r(r(r(n)+1)+1)+1)+1)+1, where A141468(n)=r(n)=n-th nonprime. 0
1, 34, 49, 51, 52, 63, 70, 77, 86, 88, 91, 94, 95, 105, 116, 118, 121, 123, 124, 125, 133, 135, 143, 153, 154, 160, 161, 162, 165, 172, 175, 177, 185, 188, 195, 201, 203, 206, 207, 208, 217, 219, 222, 225, 236, 238, 244, 248, 250, 253, 255, 260, 261, 262, 265 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

If n = 1, then

r(r(r(r(r(1)+1)+1)+1)+1)+1 = r(r(r(r(0+1)+1)+1)+1)+1 = r(r(r(r(1)+1)+1)+1)+1 = r(r(r(0+1)+1)+1)+1 = r(r(r(1)+1)+1)+1 = r(r(0+1)+1)+1 = r(r(1)+1)+1 = r(0+1)+1 = r(1)+1 = 0+1 = 1 = a(1).

If n = 2, then

r(r(r(r(r(2)+1)+1)+1)+1)+1 = r(r(r(r(1+1)+1)+1)+1)+1 = r(r(r(r(2)+1)+1)+1)+1 = r(r(r(1+1)+1)+1)+1 = r(r(r(2)+1)+1)+1 = r(r(1+1)+1)+1 = r(r(2)+1)+1 = r(1+1)+1 = r(2)+1 = 1+1 = 2

(prime).

If n = 3, then

r(r(r(r(r(3)+1)+1)+1)+1)+1 = r(r(r(r(4+1)+1)+1)+1)+1 = r(r(r(r(5)+1)+1)+1)+1 = r(r(r(8+1)+1)+1)+1 = r(r(r(9)+1)+1)+1 = r(r(14+1)+1)+1 = r(r(15)+1)+1 = r(22+1)+1 = r(23)+1 = 33+1 = 34 = a(2).

If n = 4, then

r(r(r(r(r(4)+1)+1)+1)+1)+1 = r(r(r(r(6+1)+1)+1)+1)+1 = r(r(r(r(7)+1)+1)+1)+1 = r(r(r(10+1)+1)+1)+1 = r(r(r(11)+1)+1)+1 = r(r(16+1)+1)+1 = r(r(17)+1)+1 = r(25+1)+1 = r(26)+1 = 36+1 = 37

(prime).

If n = 5, then

r(r(r(r(r(5)+1)+1)+1)+1)+1 = r(r(r(r(8+1)+1)+1)+1)+1 = r(r(r(r(9)+1)+1)+1)+1 = r(r(r(14+1)+1)+1)+1 = r(r(r(15)+1)+1)+1 = r(r(22+1)+1)+1 = r(r(23)+1)+1 = r(33+1)+1 = r(34)+1 = 48+1 = 49 = a(3).

If n = 6, then

r(r(r(r(r(6)+1)+1)+1)+1)+1 = r(r(r(r(9+1)+1)+1)+1)+1 = r(r(r(r(10)+1)+1)+1)+1 = r(r(r(15+1)+1)+1)+1 = r(r(r(16)+1)+1)+1 = r(r(24+1)+1)+1 = r(r(25)+1)+1 = r(35+1)+1 = r(36)+1 = 50+1 = 51 = a(4).

If n = 7, then

r(r(r(r(r(7)+1)+1)+1)+1)+1 = r(r(r(r(10+1)+1)+1)+1)+1 = r(r(r(r(11)+1)+1)+1)+1 = r(r(r(16+1)+1)+1)+1 = r(r(r(17)+1)+1)+1 = r(r(25+1)+1)+1 = r(r(26)+1)+1 = r(36+1)+1 = r(37)+1 = 51+1 = 52 = a(5).

If n = 8, then

r(r(r(r(r(8)+1)+1)+1)+1)+1 = r(r(r(r(12+1)+1)+1)+1)+1 = r(r(r(r(13)+1)+1)+1)+1 = r(r(r(20+1)+1)+1)+1 = r(r(r(21)+1)+1)+1 = r(r(30+1)+1)+1 = r(r(31)+1)+1 = r(44+1)+1 = r(45)+1 = 62+1 = 63 = a(6).

If n = 9, then

r(r(r(r(r(9)+1)+1)+1)+1)+1 = r(r(r(r(14+1)+1)+1)+1)+1 = r(r(r(r(15)+1)+1)+1)+1 = r(r(r(22+1)+1)+1)+1 = r(r(r(23)+1)+1)+1 = r(r(33+1)+1)+1 = r(r(34)+1)+1 = r(48+1)+1 = r(49)+1 = 66+1 = 67

(prime).

If n = 10, then

r(r(r(r(r(10)+1)+1)+1)+1)+1 = r(r(r(r(15+1)+1)+1)+1)+1 = r(r(r(r(16)+1)+1)+1)+1 = r(r(r(24+1)+1)+1)+1 = r(r(r(25)+1)+1)+1 = r(r(35+1)+1)+1 = r(r(36)+1)+1 = r(50+1)+1 = r(51)+1 = 69+1 = 70 = a(7)

If n = 11, then

r(r(r(r(r(11)+1)+1)+1)+1)+1 = r(r(r(r(16+1)+1)+1)+1)+1 = r(r(r(r(17)+1)+1)+1)+1 = r(r(r(25+1)+1)+1)+1 = r(r(r(26)+1)+1)+1 = r(r(36+1)+1)+1 = r(r(37)+1)+1 = r(51+1)+1 = r(52)+1 = 70+1 = 71(prime),

etc.

CROSSREFS

Cf. A000040, A141468.

Sequence in context: A045256 A302002 A260475 * A260468 A051991 A214473

Adjacent sequences:  A107352 A107353 A107354 * A107356 A107357 A107358

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Aug 25 2008

EXTENSIONS

Removed 36, inserted 121 and 160 by R. J. Mathar, Sep 05 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 21 04:22 EST 2019. Contains 329350 sequences. (Running on oeis4.)