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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A058012 Consider the sequence {b(m)} of composite numbers (excluding 1); sequence gives values of m where gcd{m, b(m)} increases. 1
4, 6, 10, 12, 14, 36, 39, 42, 45, 48, 124, 128, 132, 140, 345, 365, 370, 375, 380, 385, 390, 1086, 1140, 3101, 3122, 8416, 8480, 24309, 24318, 64550, 64560, 64570, 64590, 64600, 64660, 64730, 175208, 175219, 175230, 176616, 480876, 480888, 480948 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..43.

EXAMPLE

a(4) = 12 because twelve is the sixth composite number and the GCD(6,12) > GCD(5,10).

MATHEMATICA

r=0; Do[a = GCD[n, n - PrimePi[n] -1]; If[a > r, r = a; Print[n]], {n, 1, 10^6} ]

CROSSREFS

Cf. A058011.

Sequence in context: A026402 A036438 A066190 * A026411 A020189 A166986

Adjacent sequences:  A058009 A058010 A058011 * A058013 A058014 A058015

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Nov 13 2000

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 June 17 04:26 EDT 2019. Contains 324183 sequences. (Running on oeis4.)