login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A073917
Smallest prime which leaves a remainder 1 when divided by primorial(n), i.e., when divided by first n primes.
9
3, 7, 31, 211, 2311, 120121, 4084081, 106696591, 892371481, 71166625531, 200560490131, 29682952539241, 2129751844690471, 78496567990020181, 8608456956238879741, 97767475431570134191, 9613801750771063195351
OFFSET
1,1
COMMENTS
Let Pr(n) = the product of first n primes. Then a(n) is the smallest prime of the form k*Pr(n) + 1. k = 1 for first five terms.
Smallest prime p such that the prime factorization of p-1 contains the first n primes. - R. J. Mathar, Jul 03 2012
PROG
(PARI) a(n)=if(n<0, 0, s=1; while(prime(s)%prod(i=1, n, prime(i))>1, s++); s)
CROSSREFS
Cf. A002110 (primorials), A073915, A103783, A214089.
Cf. A076689 (values of k).
Sequence in context: A093441 A087864 A066676 * A030521 A105767 A063896
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 18 2002
EXTENSIONS
More terms from Vladeta Jovovic, Aug 20 2002
STATUS
approved