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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). 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..30.

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

CROSSREFS

Inspired by A007459 and A057459.

Sequence in context: A216826 A030087 A106864 * A255595 A085682 A267505

Adjacent sequences:  A282024 A282025 A282026 * A282028 A282029 A282030

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Feb 13 2017

EXTENSIONS

Corrected and extended by Robert Israel, Mar 17 2017

STATUS

approved

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Last modified December 13 19:20 EST 2017. Contains 295976 sequences.