

A136349


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


10




OFFSET

1,1


COMMENTS

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.
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
The next 7 terms in the sequence are a(7) = p# 2..89 (shown in full above), a(8) = p# 2..317, a(9) = p# 2..337, a(10) = p# 2..991, a(11) = p# 2..1873, a(12) = p# 2..2053, a(13) = p# 2..2377, where p# indicates a primorial.  Jeff Hall, Apr 05 2021


LINKS



FORMULA



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



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



