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 A136349 Numbers k of the form Product_{j=1..m} prime(j) such that k-1 is prime. 10
 6, 30, 2310, 30030, 304250263527210, 23768741896345550770650537601358310 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(7) = 1 9361386640 7008231634 7142505431 2320082662 8976125715 6376190696 2414215012 3698566371 7909694733 5243680669 6075314756 2914824028 4399976570 - copied from Data field by Michael B. Porter, Mar 30 2013 Next term (a(8)) is too large to be included: see A006794. - M. F. Hasler, May 02 2008 This sequence is different from A121069 and A002110. Compute the product of k consecutive sequences of prime factors 2,3,5,7, etc. where k=1,2,3,4,5, etc. When N is preceded by prime N-1 add N to the sequence. LINKS FORMULA a(n) = A057705(n) + 1 = A034386( A006794(n) ). - M. F. Hasler, May 02 2008 EXAMPLE a(3)=30 where the prime factors are 2,3,5; since N-1=29, prime, N=30 is added to the sequence. MATHEMATICA Select[FoldList[Times, 1, Prime[Range[70]]], PrimeQ[#-1]&]  (* Harvey P. Dale, Jan 09 2011 *) PROG (PARI) c=0; t=1; vector(7, n, until( ispseudoprime( -1+t*=prime(c++)), ); t) CROSSREFS Cf. A136350, A136351, A136352, A002110, A121069. Sequence in context: A200894 A202861 A088256 * A119411 A036285 A101340 Adjacent sequences:  A136346 A136347 A136348 * A136350 A136351 A136352 KEYWORD nonn AUTHOR Enoch Haga, Dec 25 2007 EXTENSIONS Edited by M. F. Hasler, May 02 2008, May 30 2008 STATUS approved

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Last modified August 18 07:11 EDT 2019. Contains 326072 sequences. (Running on oeis4.)