login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A051317
Euclid-Mullin sequence (A000945) with initial value a(1)=41 instead of a(1)=2.
1
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
1,1
LINKS
MATHEMATICA
a[1]=41; 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
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
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved