OFFSET
1,1
COMMENTS
a(34) is a 95-digit prime.
LINKS
Tyler Busby, Table of n, a(n) for n = 1..42 (terms 1..39 from Robert Price)
FORMULA
a(n) = A020639(1 + Product_{k=1..n-1} a(k)), a(1) = 37.
MATHEMATICA
a[1]=37; a[n_] := First[ Flatten[ FactorInteger[ 1+Product[ a[ j ], {j, n-1} ] ] ] ]; Array[a, 15]
PROG
(PARI) spf(n)=my(f=factor(n)[1, 1]); f; \\ A020639
first(m)=my(v=vector(m)); v[1]=37; for(i=2, m, v[i]=spf(1+prod(j=1, i-1, v[j]))); v \\ Anders Hellström, Nov 26 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved