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!)
A029558 Quasi-Carmichael numbers to base 5: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-5|n-5. 2
77, 221, 2093, 3311, 8897, 10373, 33143, 35717, 48581, 52421, 54677, 61997, 65021, 73337, 108383, 112217, 119621, 134357, 143429, 155237, 200777, 214709, 238901, 252197, 261749, 283871, 302789, 358853, 363263, 378437, 388841, 407813, 420893 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If multiples of 2 and 3 are not excluded, then terms like 21, 1677, 3477, 75621,... belong to the sequence. - Giovanni Resta, May 21 2013

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..6707 (terms < 10^12)

Index entries for sequences related to Carmichael numbers.

MATHEMATICA

qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && d < Min[p] && And @@ IntegerQ /@ ((n - d)/(p - d))]; Select[Range[10^6], qcm[#, 5] &] (* Giovanni Resta, May 21 2013 *)

CROSSREFS

Sequence in context: A044409 A044790 A255095 * A156652 A298102 A158767

Adjacent sequences:  A029555 A029556 A029557 * A029559 A029560 A029561

KEYWORD

nonn

AUTHOR

David W. Wilson

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 February 27 11:38 EST 2021. Contains 341656 sequences. (Running on oeis4.)