A394472 - OEIS

%I #54 Apr 18 2026 09:46:02

%S 2,12,280,8316,1065900,42948360,6377779296,347154538500,

%T 62927601396660,28577329341561000,2141057217008209500,

%U 1039622183065254234600,215439255814462529850000,21146215295244944033167500,5298886203137347121867065500,3103158113448130706101738605000

%N a(n) = Product_{k=1..n} (2*prime(n)-prime(k)).

%H Amiram Eldar, <a href="/A394472/b394472.txt">Table of n, a(n) for n = 1..289</a>

%e For n = 7, prime(7) = 17 and 2*prime(7) = 2*17 = 34 and (34-2)*(34-3)*(34-5)*(34-7)*(34-11)*(34-13)*(34-17) = 6377779296; so a(7) = 6377779296.

%t a[n_]:=Product[2*Prime[n]-Prime[k],{k,1,n}];Array[a,16] (* _James C. McMahon_, Mar 25 2026 *)

%Y Cf. A000040.

%K nonn,easy

%O 1,1

%A _Ahmad J. Masad_, Mar 21 2026