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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139072 Smallest parameter k such that (n+k!)/n is prime. 6
1, 2, 3, 4, 7, 3, 11, 7, 8, 5, 13, 4, 28, 10, 7, 8, 43, 6, 21, 5, 7, 16, 48, 4, 14, 17, 9, 7, 241, 5, 61, 11, 17, 17, 8, 10, 44, 38, 16, 6, 131, 9, 63, 12, 6, 43, 73, 9, 15, 10, 19, 14, 64, 11, 12, 9, 24, 32, 641, 5, 89, 31, 8, 8, 14, 11, 71, 19, 25, 7, 151, 6, 78, 62, 15, 35, 15, 22, 87 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) >= A002034(n). [Charles R Greathouse IV, Jul 15 2011]

LINKS

Table of n, a(n) for n=1..79.

MATHEMATICA

a = {}; Do[k = 1; While[ ! PrimeQ[(k! + n)/n], k++ ]; AppendTo[a, k], {n, 1, 100}]; a (*Artur Jasinski*)

PROG

(PARI) pr(n)=denominator(n)==1 && ispseudoprime(n)

a(n)=my(k); until(pr(k++!/n+1), ); k \\ Charles R Greathouse IV, Jul 15 2011

CROSSREFS

Cf. A082672, A089085, A089130, A117141, A007749, A139056-A139066, A020458, A139068, A137390, A139070-A139075, A136019, A136020, A136026, A136027.

Sequence in context: A274767 A058315 A072717 * A021430 A297110 A267695

Adjacent sequences:  A139069 A139070 A139071 * A139073 A139074 A139075

KEYWORD

nonn

AUTHOR

Artur Jasinski, Apr 07 2008

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 January 17 18:48 EST 2019. Contains 319251 sequences. (Running on oeis4.)