login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A100386 Numbers n such that for m=n to n+9, A006530(m) decreases. 3
586951, 1473257, 4982941, 13565441, 24954141, 25384714, 26576686, 32026196, 35797623, 35953989, 37972276, 39048260, 51755761, 58769257, 60682681, 71342703, 77863117, 80826231, 84766857, 89768134, 98363506, 110482826, 115045547, 115898807, 120797465 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A006530(n) is the largest prime factor of n.

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

EXAMPLE

586951 is here because the largest prime factors of 586951..586960 are 586951,73369,21739,9467,1319,1193,1181,1091,677,29.

MATHEMATICA

<<NumberTheory`NumberTheoryFunctions` {ta={{0}}, tm=TimeUsed[]}; mxp[x_] :=Max[PrimeFactorList[x]] Do[g=n; s1=mxp[n]; s2=mxp[n+1]; s3=mxp[n+2]; s4=mxp[n+3]; s5=mxp[n+4]; s6=mxp[n+5]; s7=mxp[n+6]; s8=mxp[n+7]; s9=mxp[n+8]; s10=mxp[n+9]; If[ !Greater[s2, s1]&&!Greater[s3, s2]&&!Greater[s4, s3]&& !Greater[s5, s4]&&!Greater[s6, s5]&&!Greater[s7, s6]&& !Greater[s8, s7]&&!Greater[s9, s8]&&!Greater[s10, s9], Print[{n, {s1, s2, s3, s4, s5, s6, s7, s8, s9, s10}}]; ta=Append[ta, n]], {n, 586950, 21977000}]; ta

Position[Partition[Table[FactorInteger[n][[-1, 1]], {n, 121*10^6}], 10, 1], _?(Max[Differences[#]]<0&), {1}, Heads->False]//Flatten (* Harvey P. Dale, Sep 18 2016 *)

CROSSREFS

Cf. A006530, A070087, A071870, A100385.

Sequence in context: A254481 A183968 A104962 * A205214 A206222 A202160

Adjacent sequences:  A100383 A100384 A100385 * A100387 A100388 A100389

KEYWORD

nonn

AUTHOR

Labos Elemer, Dec 09 2004

EXTENSIONS

Edited by Don Reble, Jun 13 2007

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 9 21:08 EDT 2022. Contains 356026 sequences. (Running on oeis4.)