A051324 Euclid-Mullin sequence (A000945) with initial value a(1)=71 instead of a(1)=2.

71, 2, 11, 3, 43, 201499, 67, 5, 487, 19, 967, 13, 131, 17, 3523392679146994953040171, 7, 633046028131441, 197, 1313225762816449, 22441, 29, 7039, 2357, 12264112894355231632110401532068053014661

Offset: 1

Author

Labos Elemer

Keywords

• nonn

Links

• Tyler Busby, Table of n, a(n) for n = 1..44 (terms 1..29 from Robert Price)

Crossrefs

Cf. A000945, A000946, A005265, A005266.

Programs

Mathematica

a[1]=71; 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]=71; for(i=2, m, v[i]=spf(1+prod(j=1, i-1, v[j]))); v \\ Anders Hellström, Dec 04 2015

Extensions

a(24) from Robert Price, Jul 11 2015