|
%I #8 Feb 18 2015 11:02:09
%S 6,30,2310,510510,200560490130,304250263527210,1922760350154212639070,
%T 7858321551080267055879090,267064515689275851355624017992790,
%U 279734996817854936178276161872067809674997230
%N Product of the first prime(n) primes.
%D A. Fletcher, J. C. P. Miller, L. Rosenhead and L. J. Comrie, An Index of Mathematical Tables. Vols. 1 and 2, 2nd ed., Blackwell, Oxford and Addison-Wesley, Reading, MA, 1962, Vol. 1, p. 50.
%F a(n) = p(p[n])#, where p[n] is the n-th prime number and where p(m)# is the m-th primorial number (Cf. A002110).
%e a(1) = p(p(1))# = p(2)# (because p(1) = 2 is the first prime number) = 2* 3 = 6 (by the definition of primorial, see A002110); that is, the product of the first 2 prime numbers.
%e a(2) = p(p(2))# = p(3)# = 2 * 3 * 5 = 30 = the product of the first 3 primes.
%e a(3) = 2 * 3 * 5 * 7 * 11 = 2310 = the product of the first 5 primes.
%e a(4) = 2 * 3 * 5 * 7 * 11 * 13 * 17 = 510510 = product of first 7 primes.
%t Array[Times @@ Array[Prime, Prime@# ] &, 10] (* _Robert G. Wilson v_, Jul 27 2006 *)
%Y Cf. A002110.
%K easy,nonn
%O 1,1
%A _Walter Carlini_, Jul 26 2006
%E a(10) from _Robert G. Wilson v_, Jul 27 2006
| 