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A070858 Smallest prime == 1 mod L, where L = LCM of 1 to n. 6
2, 3, 7, 13, 61, 61, 421, 2521, 2521, 2521, 55441, 55441, 4324321, 4324321, 4324321, 4324321, 85765681, 85765681, 232792561, 232792561, 232792561, 232792561, 10708457761, 10708457761, 26771144401, 26771144401, 401567166001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Beginning with 3, smallest prime p = a(n) such that p + k is divisible by k + 1 for each k = 1, 2, ..., n. For example: 61 --> 62, 63, 64, 65 and 66 are divisible respectively by 2, 3, 4, 5 and 6. - Robin Garcia, Jul 23 2012

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..200

MAPLE

A070858 := proc(n)

    local l, p;

    l := ilcm(seq(i, i=1..n)) ;

    for p from 1 by l do

        if isprime(p) then

            return p;

        end if;

    end do:

end proc; # R. J. Mathar, Jun 25 2013

PROG

(PARI) a(n)=my(L=lcm(vector(n, i, i)), k=1); while(!ispseudoprime(k+=L), ); k \\ Charles R Greathouse IV, Jun 25 2013

CROSSREFS

Cf. A060357, A075059, A003418, A070844 to A070856, A035091.

Sequence in context: A257393 A273814 A085872 * A061067 A104366 A104367

Adjacent sequences:  A070855 A070856 A070857 * A070859 A070860 A070861

KEYWORD

nonn

AUTHOR

Amarnath Murthy, May 16 2002

EXTENSIONS

More terms from Sascha Kurz, Feb 02 2003

STATUS

approved

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Last modified June 15 20:50 EDT 2019. Contains 324145 sequences. (Running on oeis4.)