OFFSET
0,2
COMMENTS
EXAMPLE
a(5) = 5*7*11*13*17 = 85085.
MATHEMATICA
a[n_] := Module[{p = Prime@Range[n]}, While[Times@@(1+1/p) >= 2, p = Rest @ AppendTo[p, NextPrime@p[[-1]]]]; Times@@p]; Array[a, 18, 0] (* Amiram Eldar, Jul 04 2019 *)
PROG
(PARI) a(n)=for(k=1, +oo, p=prod(i=k, k+n-1, prime(i)); sigma(p)<2*p && return(p))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jeppe Stig Nielsen, Jul 01 2019
STATUS
approved