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A282027
a(n+1) = smallest prime p > a(n) such that p-1 divides a(1)*a(2)*...*a(n); or if no such prime p exists, then a(n+1) = smallest prime > a(n).
3
2, 3, 7, 43, 47, 283, 659, 1319, 1699, 9227, 11887, 55399, 71359, 159707, 396719, 558643, 793439, 794039, 1117379, 1117943, 1143887, 2235887, 5554067, 6707747, 6863323, 13734803, 15667447, 16663963, 18214099, 20123239, 45196799, 46954223, 55937239, 93908447
OFFSET
1,1
LINKS
MAPLE
A[1]:= 2: P:= 1:
for n from 2 to 30 do
P:= A[n-1]*P;
p0:= nextprime(A[n-1]);
p:= p0;
while p-1 <= P and P mod (p-1) <> 0 do
p:= nextprime(p)
od:
if p-1 > P then A[n]:= p0
else A[n]:= p
fi;
od:
seq(A[i], i=1..30); # Robert Israel, Mar 17 2017
PROG
(PARI) lista(nn) = {my(d, k, m, t, v=List([2])); for(n=2, nn, k=1; m=oo; while((d=prod(i=1, t=k, v[i]))<m && k++<n, until(v[t]*d>m || t==n-1, t++); forsubset([t, k], w, if(ispseudoprime(d=prod(i=1, k, v[w[i]])+1) && d>v[n-1], m=min(m, d)))); listput(v, if(m<oo, m, nextprime(v[n-1]+1)))); v; } \\ Jinyuan Wang, Nov 21 2020
CROSSREFS
Inspired by A007459 and A057459.
Sequence in context: A216826 A030087 A106864 * A255595 A085682 A267505
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 13 2017
EXTENSIONS
Corrected and extended by Robert Israel, Mar 17 2017
More terms from Jinyuan Wang, Nov 21 2020
STATUS
approved