OFFSET
1,1
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..37
Romeo Meštrović, Euclid's theorem on the infinitude of primes: a historical survey of its proofs (300 BC--2012) and another new proof, arXiv preprint arXiv:1202.3670 [math.HO], 2012-2023. - From N. J. A. Sloane, Jun 13 2012
Carlos Rivera, Puzzle 118. Primorial product numbers, The Prime Puzzles & Problems Connection.
Eric Weisstein's World of Mathematics, Primorial.
EXAMPLE
a(3)=361 since 361 = (2)*(2*3)*(2*3*5) + 1.
MATHEMATICA
Table[Times@@Table[Times@@Prime[Range[n]], {n, k}]+1, {k, 40}] (* Jayanta Basu, May 12 2013 *)
Rest[FoldList[Times, 1, Rest[FoldList[Times, 1, Prime[Range[10]]]]]]+1 (* Harvey P. Dale, Sep 16 2013 *)
PROG
(PARI) { p=1; q=1; for (n=1, 37, p*=prime(n); q*=p; write("b066266.txt", n, " ", q + 1) ) } \\ Harry J. Smith, Feb 08 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick De Geest, Dec 16 2001
EXTENSIONS
Offset changed from 0 to 1 by Harry J. Smith, Feb 08 2010
STATUS
approved