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Product of primes between n and n^2.
2

%I #15 Nov 18 2024 12:18:21

%S 1,6,105,5005,37182145,6685349671,20496326086283047,

%T 558516101711461766587,15322117939717490037614688353,

%U 10978895066407230594062391177770267,150524069716274322800691458531160297587022319,4335344870389259769484516507207766258600144871515339

%N Product of primes between n and n^2.

%H Alois P. Heinz, <a href="/A109819/b109819.txt">Table of n, a(n) for n = 1..48</a>

%e a(3) = 105 because 3, 5 and 7 are the A073882(3) = 3 primes in the interval from 3 to 3^2 inclusive and 3 * 5 * 7 = 105.

%t Join[{1},Table[Product[Prime[i],{i,If[PrimeQ[n],PrimePi[n],PrimePi[n]+1],PrimePi[n^2]}],{n,2,10}]] (* _James C. McMahon_, Apr 01 2024 *)

%o (PARI) for(n=1,15,print1(prod(k=n,n^2,if(isprime(k),k,1)),","))

%Y Cf. A109818 (sum of same primes), A073882 (number of primes between n and n^2).

%K easy,nonn,changed

%O 1,2

%A _Rick L. Shepherd_, Jul 02 2005

%E More terms from _Michel Marcus_, Apr 02 2024