login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098651 Where A098650 reaches a record. 2
1, 2, 6, 15, 30, 39, 78, 105, 910, 7735, 18655, 98605 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..12.

MATHEMATICA

(* first do *) Needs["NumberTheory`NumberTheoryFunctions`"] (* then *) PrimeFactors[n_] := Flatten[ Table[ # [[1]], {1} ] & /@ FactorInteger[ n ]]; f[n_] := Block[{k = n + 1}, If[EvenQ[k], k++ ]; While[ PrimeQ[k] || Union[ PowerMod[ PrimeFactors[n], k - 1, k]] != {1}, k += 2]; k]; a = {1}; b = {9}; Do[ If[ SquareFreeQ[n], c = f[n]; If[c > b[[ -1]], AppendTo[a, n]; AppendTo[b, c]; Print[n]]], {n, 2, 145000}]; a

CROSSREFS

Cf. A098650, A098652.

Sequence in context: A331773 A033286 A182724 * A087427 A031126 A289373

Adjacent sequences:  A098648 A098649 A098650 * A098652 A098653 A098654

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 18 2004

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 April 5 23:04 EDT 2020. Contains 333260 sequences. (Running on oeis4.)