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!)
A181667 Least integer m > 0 such that none of the first n primes divides any value of the polynomial x^2 + x + m. 2
1, 5, 11, 11, 17, 17, 41, 41, 41, 41, 41, 41, 19421, 19421, 333491, 601037, 601037, 5237651, 9063641, 12899891, 24073871, 24073871, 28537121, 67374467, 67374467, 67374467, 67374467, 146452961, 13236860171, 13236860171, 17959429571, 57391479317, 57391479317 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

All the elements of this sequence with n > 2 are congruent mod 30 to one of the polynomials x^2 + x + 11 or x^2 + x + 17.

The elements of the sequence have been taken from A060392, see below.

LINKS

William P. Orrick, Table of n, a(n) for n = 1..59

M. J. Jacobson, Jr., Master's Thesis, University of Manitoba, 1995. (See Table 6.6, which lists values of 4a(n)-1.)

EXAMPLE

x^2 + x + 11 takes the values 11, 13, 17, 23, 31, 41, 53, 67, 83, ... never divisible by any of the primes 2, 3, or 5.

CROSSREFS

a(n) equals min_{k > n} A060392(k).

Sequence in context: A061768 A205673 A245098 * A060846 A113002 A179618

Adjacent sequences:  A181664 A181665 A181666 * A181668 A181669 A181670

KEYWORD

nonn

AUTHOR

Esteban Crespi de Valldaura, Feb 04 2011

EXTENSIONS

a(29) corrected and more terms added by William P. Orrick, Mar 17 2017

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 July 26 08:42 EDT 2021. Contains 346294 sequences. (Running on oeis4.)