A051317 Euclid-Mullin sequence (A000945) with initial value a(1)=41 instead of a(1)=2.

41, 2, 83, 3, 7, 47, 71, 29, 653, 5, 173, 23, 103058819, 11, 389, 73161901, 168593357, 13, 45613, 347, 211, 53, 400947612985987, 28837, 35111, 913011302795748880783905085999338914209329333652950191830525020998365540320068611

Offset: 1

Author

Labos Elemer

Keywords

• easy
• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..37

Crossrefs

Cf. A000945, A000946, A005265, A005266.

Programs

Mathematica

a[1]=41; a[n_] := First[ Flatten[ FactorInteger[ 1+Product[ a[ j ], {j, n-1} ] ] ] ]; Array[a, 15]

PARI

spf(n)=my(f=factor(n)[1, 1]); f
first(m)=my(v=vector(m)); v[1]=41; for(i=2, m, v[i]=spf(1+prod(j=1, i-1, v[j]))); v \\ Anders Hellström, Nov 26 2015