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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A074380 Sarrus numbers n (A001567) which satisfy mu(n) = -1 and which are not Super-Poulet numbers (A050217). 2
561, 645, 1105, 1729, 1905, 2465, 2821, 4371, 6601, 8481, 8911, 10585, 12801, 13741, 13981, 15841, 16705, 25761, 29341, 30121, 30889, 33153, 34945, 41665, 46657, 52633, 57421, 68101, 74665, 83665, 87249, 88561, 91001, 93961, 113201 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Some of these are Carmichael numbers, A002997: 561, 1105, 1729, ....

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[ Range[115000], !PrimeQ[ # ] && OddQ[ # ] && PowerMod[2, # - 1, # ] == 1 && Union[ PowerMod[2, Drop[Divisors[ # ], 1], # ]] != {2} && MoebiusMu[ # ] != 1 &]

PROG

(PARI) is(n)=if(isprime(n) || Mod(2, n)^(n-1)!=1 || moebius(n)>=0, return(0)); fordiv(n, d, if(Mod(2, d)^d!=2, return(1))); 0 \\ Charles R Greathouse IV, Sep 01 2016

CROSSREFS

Cf. A001567, A050217, A002997.

Sequence in context: A192297 A080747 A306487 * A215672 A085999 A224695

Adjacent sequences:  A074377 A074378 A074379 * A074381 A074382 A074383

KEYWORD

nonn

AUTHOR

Jani Melik, Sep 24 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v, Oct 03 2002

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 October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)