A051334 Euclid-Mullin sequence (A000945) with initial value a(1)=8191 instead of a(1)=2.

8191, 2, 3, 7, 53, 1399, 5, 19, 646843, 26945441, 109, 443, 90670999, 280460690293140589, 907, 16293787, 3655513, 499483, 131, 21067, 143797, 54540542259000816707816058313971443, 392963, 977, 11, 5021, 179, 439, 353, 34417238589462247, 1193114397863177, 13, 59, 31643, 79399, 73, 43, 16639867

Offset: 1

Author

Labos Elemer

Keywords

• nonn

Links

• Sean A. Irvine, Table of n, a(n) for n = 1..59

Crossrefs

Cf. A000945, A000946, A005265, A005266.

Programs

Mathematica

a[1]=8191; a[n_] := First[ Flatten[ FactorInteger[ 1+Product[ a[ j ], {j, 1, n-1} ] ] ] ]; Array[a, 10]

PARI

spf(n)=my(f=factor(n)[1,1]);f;
first(m)={my(v=vector(m)); v[1]=8191; for(i=2, m, v[i]=spf(1+prod(j=1, i-1, v[j]))); v;} /* Anders Hellström, Aug 18 2015 */

Extensions

More terms from Sean A. Irvine, Sep 20 2012

a(30)-a(38) from Charles R Greathouse IV, Sep 21 2012