A074041 Product of first n single (i.e., non-twin) primes.

2, 46, 1702, 79994, 4239682, 284058694, 22440636826, 1862572856558, 165768984233662, 16079591470665214, 1816993836185169182, 230758217195516486114, 30229326452612659680934, 4746004253060187569906638, 773598693248810573894781994

Offset

1,1

Comments

a(n) = 5*A002110(A049084(A074038(n)))/A074040(k), where k is the largest number such that A006512(k) < A007510(n).

Links

Table of n, a(n) for n=1..15.

Formula

a(1) = A007510(1) and a(n) = a(n-1)*A007510(n) for n > 1.

Example

The first four single primes are 2, 23, 37 and 47, therefore a(4) = 2*23*37*47 = 79994.

Mathematica

nn=50; tps=Union[Flatten[Select[Partition[Prime[Range[nn]], 2, 1], Last[#]- First[#] ==2&]]]; ntps=Complement[Prime[Range[nn]], tps]; Rest[ FoldList[ Times, 1, ntps]]  (* Harvey P. Dale, Mar 31 2011 *)

Crossrefs

Sequence in context: A279524 A264500 A173586 * A277554 A000191 A000192

Adjacent sequences: A074038 A074039 A074040 * A074042 A074043 A074044

Keyword

nonn

Author

Reinhard Zumkeller, Aug 13 2002

Extensions

More terms from Harvey P. Dale, Mar 31 2011

Status

approved