

A136349


Numbers k of the form Product_{j=1..m} prime(j) such that k1 is prime.


10




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 N1 add N to the sequence.


LINKS

Table of n, a(n) for n=1..6.


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 N1=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



